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Kids learn about the planet Venus of the Solar System including fun facts, mass, day, year, and distance from the Sun. Astronomy for kids and teachers.

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https://www.ducksters.com/science/mercury.php

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Kids learn about the planet Mercury of the Solar System including fun facts, mass, day, year, and distance from the Sun. Astronomy for kids and teachers.

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https://www.ducksters.com/science/earth.php

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Kids learn about the planet Earth of the Solar System including fun facts, mass, day, year, and distance from the Sun. Astronomy for kids and teachers.

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https://www.ducksters.com/science/mars.php

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https://www.ducksters.com/science/jupiter.php

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Kids learn about the planet Jupiter of the Solar System including fun facts, mass, day, year, and distance from the Sun. Astronomy for kids and teachers.

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https://www.ducksters.com/science/saturn.php

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https://www.ducksters.com/science/neptune.php

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Kids learn about the ice giant planet Neptune of the Solar System including fun facts, mass, day, year, and distance from the Sun. Astronomy for kids and teachers.

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https://spaceplace.nasa.gov/all-about-venus/en/

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Even though Venus isn't the closest planet to the Sun, it is still the hottest. It has a thick atmosphere full of the greenhouse gas carbon dioxide and clouds made of sulfuric acid. The gas traps heat and keeps Venus toasty warm. In fact, it's so hot on Venus, metals like lead would be puddles of melted liquid.

Venus looks like a very active planet. It has mountains and volcanoes. Venus is similar in size to Earth. Earth is just a little bit bigger.

Venus is unusual because it spins the opposite direction of Earth and most other planets. And its rotation is very slow. It takes about 243 Earth days to spin around just once. Because it's so close to the Sun, a year goes by fast. It takes 225 Earth days for Venus to go all the way around the Sun. That means that a day on Venus is a little longer than a year on Venus.

Since the day and year lengths are similar, one day on Venus is not like a day on Earth. Here, the Sun rises and sets once each day. But on Venus, the Sun rises every 117 Earth days. That means the Sun rises two times during each year on Venus, even though it is still the same day on Venus! And because Venus rotates backwards, the Sun rises in the west and sets in the east.

Just like Mercury, Venus doesn't have any moons.

Structure and Surface

Venus is the hottest planet in our solar system.

Venus is a terrestrial planet. It is small and rocky.

Venus has a thick atmosphere. It traps heat and makes Venus very hot.

Venus has an active surface, including volcanoes!

Venus spins the opposite direction of Earth and most other planets.

Time on Venus

A day on Venus lasts 243 Earth days.

A year on Venus lasts 225 Earth days.

Venus's Neighbors

Venus does not have any moons.

Venus is the second planet from the Sun. That means Mercury and Earth are Venus's neighboring planets.

Quick History

Venus has been known since ancient times because it can be seen easily without a telescope.

Venus has been visited by several spacecraft: Mariner 2, Mariner 5, Mariner 10, Pioneer Venus 1, Pioneer Venus 2, and an orbiter called Magellan.

What does Venus look like?

For more information visit:
NASA Solar System Exploration

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https://spaceplace.nasa.gov/all-about-mercury/en/

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Mercury is the smallest planet in our solar system. It's just a little bigger than Earth's moon. It is the closest planet to the sun, but it's actually not the hottest. Venus is hotter.

Along with Venus, Earth, and Mars, Mercury is one of the rocky planets. It has a solid surface that is covered with craters. It has no atmosphere, and it doesn't have any moons. Mercury likes to keep things simple.

This small planet spins around slowly compared to Earth, so one day lasts a long time. Mercury takes 59 Earth days to make one full rotation. A year on Mercury goes by fast. Because it's the closest planet to the sun, it doesn't take very long to go all the way around. It completes one revolution around the sun in just 88 Earth days. If you lived on Mercury, you'd have a birthday every three months!

A day on Mercury is not like a day here on Earth. For us, the sun rises and sets each and every day. Because Mercury has a slow spin and short year, it takes a long time for the sun to rise and set there. Mercury only has one sunrise every 180 Earth days! Isn't that weird?

Structure and Surface

Mercury is the smallest planet in our solar system.

Mercury is a terrestrial planet. It is small and rocky.

Mercury doesn't really have an atmosphere.

Time on Mercury

A day on Mercury lasts 59 Earth days.

A year on Mercury lasts 88 Earth days.

Mercury's Neighbors

Mercury does not have any moons.

Mercury is the closest planet to the sun.

Venus is Mercury's neighboring planet.

Quick History

Mercury has been known since ancient times because it can be seen without advanced telescopes.

Mercury has been visited by two spacecraft: Mariner 10 and MESSENGER.

What does Mercury look like?

For more information visit:
NASA Solar System Exploration

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https://spaceplace.nasa.gov/all-about-earth/en/

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Our home planet Earth is a rocky, terrestrial planet. It has a solid and active surface with mountains, valleys, canyons, plains and so much more. Earth is special because it is an ocean planet. Water covers 70% of Earth's surface.

Our atmosphere is made mostly of nitrogen and has plenty of oxygen for us to breathe. The atmosphere also protects us from incoming meteoroids, most of which break up in our atmosphere before they can strike the surface as meteorites.

Since we live here, you might think we know all there is to know about Earth. Not at all, actually! We have a lot we can learn about our home planet. Right now, there are many satellites orbiting Earth taking pictures and measurements. This is how we can learn more about weather, oceans, soil, climate change, and many other important topics.

Structure and Surface

Earth is a terrestrial planet. It is small and rocky.

Earth's atmosphere is the right thickness to keep the planet warm so living things like us can be there. It's the only planet in our solar system we know of that supports life. It is mostly nitrogen, and it has plenty of oxygen for us to breathe.

Time on Earth

A day on Earth lasts a little under 24 hours.

One year on Earth lasts 365.25 days. That 0.25 extra means every four years we need to add one day to our calendar. We call it a leap day (in a leap year).

Earth's Neighbors

Earth has just one Moon. It is the only planet to have just one moon.

Earth has lots of spacecraft watching it. There is still a lot we can learn about our home planet.

Earth is the third planet from the Sun in our solar system. That means Venus and Mars are Earth's neighboring planets.

Quick History

We have known about our planet since ancient times, of course. But we didn't know our place in the solar system for a long time.

What does Earth look like?

For more information visit:
NASA Solar System Exploration

Related Resources for Educators

Real World: A-Train
Our World: A-Train
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https://spaceplace.nasa.gov/all-about-mars/en/

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All About Mars | NASA Space Place – NASA Science for Kids

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https://spaceplace.nasa.gov/all-about-jupiter/en/

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Jupiter is the biggest planet in our solar system. It's similar to a star, but it never got massive enough to start burning. It is covered in swirling cloud stripes. It has big storms like the Great Red Spot, which has been going for hundreds of years. Jupiter is a gas giant and doesn't have a solid surface, but it may have a solid inner core about the size of Earth. Jupiter also has rings, but they're too faint to see very well.

Structure and Surface

Jupiter is the biggest planet in our solar system.

Jupiter is a gas giant. It is made mostly of hydrogen and helium.

Jupiter has a very thick atmosphere.

Jupiter has rings, but they're very hard to see.

Time on Jupiter

One day on Jupiter goes by in just 10 hours.

One year on Jupiter is the same as 11.8 Earth years.

Jupiter's Neighbors

Jupiter has 80 confirmed moons.

Jupiter is the fifth planet from the Sun. That means Mars and Saturn are Jupiter's neighboring planets.

Quick History

Jupiter has been known since ancient times because it can be seen without advanced telescopes.

Jupiter has been visited or passed by several spacecraft, orbiters and probes, such as Pioneer 10 and 11, Voyager 1 and 2, Cassini, New Horizons, and Juno.

What does Jupiter look like?

For more information visit:
NASA Solar System Exploration

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https://spaceplace.nasa.gov/all-about-saturn/en/

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https://spaceplace.nasa.gov/all-about-uranus/en/

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Uranus is made of water, methane, and ammonia fluids above a small rocky center. Its atmosphere is made of hydrogen and helium like Jupiter and Saturn, but it also has methane. The methane makes Uranus blue.

Uranus also has faint rings. The inner rings are narrow and dark. The outer rings are brightly colored and easier to see. Like Venus, Uranus rotates in the opposite direction as most other planets. And unlike any other planet, Uranus rotates on its side.

Structure and Surface

Uranus is surrounded by a set of 13 rings.

Uranus is an ice giant (instead of a gas giant). It is mostly made of flowing icy materials above a solid core.

Uranus has a thick atmosphere made of methane, hydrogen, and helium.

Uranus is the only planet that spins on its side.

Uranus spins the opposite direction as Earth and most other planets.

Time on Uranus

One day on Uranus lasts a little over 17 hours (17 hours and 14 minutes, to be exact).

One year on Uranus is the same as 84 years on Earth. That's a long time to wait for a birthday cake.

Uranus' Neighbors

Uranus has 27 known moons.

Uranus is the seventh planet from the Sun. That means Saturn and Neptune are Uranus' neighboring planets.

Quick History

Uranus was discovered in 1781 by William Herschel in Great Britain.

Uranus has only been visited by Voyager 2.

What does Uranus look like?

For more information visit:
NASA Solar System Exploration

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https://spaceplace.nasa.gov/all-about-neptune/en/

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Neptune is dark, cold, and very windy. It's the last of the planets in our solar system. It's more than 30 times as far from the sun as Earth is. Neptune is very similar to Uranus. It's made of a thick fog of water, ammonia, and methane over an Earth-sized solid center. Its atmosphere is made of hydrogen, helium, and methane. The methane gives Neptune the same blue color as Uranus. Neptune has six rings, but they're very hard to see.

Structure and Surface

Neptune is encircled by six rings.

Neptune, like Uranus, is an ice giant. It's similar to a gas giant. It is made of a thick soup of water, ammonia, and methane flowing over a solid core about the size of Earth.

Neptune has a thick, windy atmosphere.

Time on Neptune

One day on Neptune goes by in 16 hours.

Neptune has such a long journey around the Sun it takes 165 Earth years to go around once. That's a long year!

Neptune's Neighbors

Neptune has 14 moons.

Neptune is the eighth and most distant planet from the Sun. That means Uranus is Neptune's only neighboring planet.

Quick History

Neptune was discovered in 1846 by Urbain Le Verrier, John Couch Adams, and Johann Galle.

Only Voyager 2 has visited Neptune.

What does Neptune look like?

For more information visit:
NASA Solar System Exploration

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https://www.esa.int/kids/en/learn/Our_Universe/Planets_and_moons/Venus

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Venus is the second planet from the Sun, so it is always fairly close to the Sun in the sky. It appears as a brilliant morning or evening "star" - the brightest object in the night sky apart from the Moon. In a telescope, it can be seen to go through phases, just like the Moon.

Venus is so bright because it is covered by clouds that reflect much of the incoming sunlight. The yellowish clouds are made of sulphur and sulphuric acid.

In some ways, Venus is Earth's twin. It is about the same size and made of the same rocky materials. It also comes closer to us than any other planet. However, it is blanketed with a thick atmosphere of carbon dioxide - the gas that we breathe out. This atmosphere is so dense that walking through would be like wading through water.

The carbon dioxide traps most of the heat from the Sun. The cloud layers also act as a blanket. The result is a "runaway greenhouse effect" that has caused the planet's temperature to soar to 465°C, hot enough to melt lead. This means that Venus is even hotter than Mercury.

Without special protection, a visitor to Venus would die instantly - crushed by the immense air pressure, suffocated by the atmosphere, burned to a crisp by the scorching heat, and dissolved by the acid.

The surface of Venus has been mapped by radar. The maps show thousands of volcanoes and impact craters. There are two main upland areas, with a mountain range taller than Mt. Everest.

Dozens of spacecraft have visited Venus, but many mysteries remain. ESA's Venus Express has been in near-polar orbit around the planet since it arrived in April 2006. Most of its instruments have been studying the dense atmosphere and rapidly moving clouds, or investigating how the Sun affects the planet. However, its infrared sensor has also been able to map some of the surface and show that active volcanoes may exist on Earth's neighbour.

Last modified 17 November 2010

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Venus is the second planet from the Sun, so it is always fairly close to the Sun in the sky. It appears as a brilliant morning or evening "star" - the brightest object in the night sky apart from the Moon. In a telescope, it can be seen to go through phases, just like the Moon.

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https://kids.nationalgeographic.com/space/article/mission-to-venus

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LOCATION: Second rock from the sun

DISTANCE FROM THE SUN: 66,782,596 to 67,693,905 miles (107,477,000 to 108,939,000 kilometers)

AVERAGE SURFACE TEMPERATURE: 867° F (462° C)

LENGTH OF SPACE JOURNEY FROM EARTH TO VENUS: 6 months

GRAVITY: If you weigh 100 pounds on Earth, you'd weigh 91 pounds here.

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Mission to Venus - Get facts about this planet

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LOCATION: Second rock from the sun DISTANCE FROM THE SUN: 66,782,596 to 67,693,905 miles (107,477,000 to 108,939,000 kilometers) AVERAGE SURFACE TEMPERATURE: 867° F (462° C) LENGTH OF SPACE JOURNEY FROM EARTH TO VENUS: 6 months GRAVITY: If you weigh 100 pounds on Earth, you'd weigh 91 pounds here.

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https://kids.nationalgeographic.com/space/article/mission-to-mercury

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LOCATION: First rock from the sun

DISTANCE FROM THE SUN: 28,583,702 to 35,983,125 miles (46,001,200 to 69,816,900 kilometers)

AVERAGE SURFACE TEMPERATURE: 243° F (117° C)

LENGTH OF SPACE JOURNEY FROM EARTH TO MERCURY: 4 years

GRAVITY: If you weigh 100 pounds on Earth, you'd weigh 38 pounds here.

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Mission to Mercury - Get facts about this planet

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Get the facts on Mercury, the closest planet to the sun.

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https://nineplanets.org/kids/mercury/

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Mercury is named after the Roman god of commerce, travel, and thievery. In Greek mythology, Mercury was known as Hermes, the messenger of the gods. It probably received this name because it moves very quickly across the sky.

Key Facts & Summary

Mercury is the closest planet to the Sun at a distance of 57 million kilometers / 35 million miles.

Out of all the terrestrial planets, Mercury is the smallest. It is also the smallest planet in the Solar System.

Despite being so small, Mercury is the second-densest planet in the Solar System after Earth. This means it is very compact.

Mercury does not have any satellites or ring systems.

The surface of Mercury is similar to the Moon. It is the most heavily cratered planet and this means that it hasn't been geologically active for many years.

Mercury has a radius of 2.439 km / 1.516 mi and a diameter of 4.879 km / 3.032 mi.

Though it is the closest planet to the Sun, temperatures on Mercury are both hot and cold.

During the day, Mercury's average surface temperatures can reach up to 800 degrees Fahrenheit / 430 degrees Celsius.

At night, Mercury's surface temperatures can drop to as low as -290 degrees Fahrenheit / -180 degrees Celsius.

Mercury's changes in temperature are the most drastic in the Solar System.

Mercury formed around 4.5 billion years ago after gravity pulled swirling gases and dust together.

After Mercury was formed, scientists believe that it suffered heavy bombardments by comets and asteroids shortly after. Another event called the Late Heavy Bombardment which ended around 3.8 billion years ago, may also be responsible for Mercury's cratered surface.

Almost 85% of Mercury's radius is represented by its enormous iron core.

Due to the core's unusual size, Mercury began to shrink as the core cooled and contracted pulling the surface inward.

Mercury is the smallest planet in the Solar System and the closest planet to the Sun. Though it is very close to the Sun, it is not the hottest planet, that title belongs to Venus, but Mercury is the second-hottest nonetheless.

Mercury is slightly bigger than Earth's Moon, and it is also very similar in appearance to our Moon. Mercury itself doesn't have any moons. The planet can be seen without binoculars or telescopes, but since it is so near to the Sun, it may be hard to see in the early evening skies.

Surface and structure

Mercury is covered with craters from various impacts. One of the largest is called the Caloris Basin, and it is 1.300 kilometers / 807 miles across.

It was probably created by a big impact long ago. Mercury has a very thin atmosphere called an exosphere. It is made out of oxygen, sodium, hydrogen, helium, and potassium.

Since its surface is similar to our Moon, it indicates that the small planet hasn't been geologically active for many years. The planet is primarily made out of rocks.

Though it is very hot on Mercury, frozen water exists on its surface. Some of the deep craters present at the poles are never exposed to direct sunlight, and temperatures remain very low there.

Time on Mercury

Mercury spins around slowly compared to Earth. One day on Mercury is 59 Earth days. However, a year on Mercury goes by fast. Because it is close to the Sun, it doesn't take very long to go all the way around it.

Mercury circles the Sun once every 88 Earth days. If you would live on Mercury, you'd have a birthday every three months! Mercury has the shortest year of any planet. It moves around the Sun with a speed of 47 kilometers / 29 miles per second.

Though on Earth, the Sun rises and sets every day, on Mercury, it takes a long time for this to happen. A sunrise happens on Mercury once every 180 Earth days.

Fun Facts

1. In ancient times, Mercury was mistakenly thought of as being two different objects in the sky: The Mourning Star and The Evening Star.

2. Mercury orbits the Sun with a speed of around 47 kilometers / 29 miles per second. It is the fastest planet.

3. It takes sunlight 3.2 minutes to travel from the Sun to Mercury. If you were on Mercury and the Sun suddenly disappeared, you would notice this only after 3.2 minutes.

4. Mercury and Venus orbit the Sun within Earth's orbit. This makes them inferior planets.

5. The crater Caloris Basin on Mercury is large enough to fit the state of Texas.

6. NASA has mapped the entire surface of Mercury.

7. Mercury's core has a higher iron content than that of any other major planet in the Solar System.

8. Sometimes, Mercury streams particles off of its surface and results in a tail, similar to a comet.

9. An event called a "transit" occurs 13 times every century making it possible to see Mercury from Earth, as it crosses the Sun's face.

Size and Comparison

We know that Mercury is the smallest planet. It has a radius of 2.439 km / 1.516 mi and a diameter of 4.879 km / 3.032 mi. But how does it compare to the other planets in the Solar System?

Both Venus and Earth are around three times bigger than Mercury. Mars is only 30% bigger than Mercury but now let's take a look at the giants of the Solar System.

Neptune and Uranus have more than 10 times the diameter of Mercury. Saturn has 23 times the diameter of Mercury while Jupiter, the biggest planet in the Solar System, has more than 29 times the diameter of Mercury. More than 24.462 Mercury's would fit inside Jupiter's volume.

Trivia

Who discovered Mercury?

The naming and discovery of Mercury cannot be attributed to anyone. The ancients knew about Mercury for many years since it is visible with the naked eye.

One of the earliest known recorded observations of Mercury is the Mul.Apin tablets. It is believed that these observations were made by an ancient Assyrian astronomer around the 14 th century BC. The translation of Mercury's name written upon those tablets translates to "the jumping planet."

Planet Nabu

The Babylonians called Mercury, Nabu. Some of their records date back to the 1 st millennium BC. Nabu is also the messenger of the gods in Babylonian mythology.

Mercury suffered a great collision

Mercury is theorized to be 4.5 billion years old. Gravity pulled the swirling gas and dust together and formed the small planet. However, Mercury has an enormous core and scientists believe that this is the result of a collision. Another giant object smashed into Mercury and stripped much of its surface.

Other Characteristics

Though Venus is the closest planet to Earth, it spends most of its time far away. This makes Mercury the nearest planet to Earth, at least for certain periods. Since Mercury has a thin atmosphere, temperatures at night drop very low, from 430 degrees Celsius during the day, to -180 degrees Celsius at night.

Mercury doesn't have any moons, and since it is very close to the Sun, it will never have. The Sun will basically steal any satellite of Mercury.

The core of Mercury has high amounts of iron, more so than any major planet in the Solar System. NASA has mapped the entire surface of Mercury, and yes, it is the most cratered planet in the Solar System.

Since Mercury is close to us, we can easily send spacecraft or probes to it. The third spacecraft set to arrive on Mercury is named BepiColombo, and it should arrive at Mercury in 2025.

Mercury Notes

Mercury is the closest planet to the Sun, but not the hottest.

It is the smallest planet in the Solar System, it doesn't experience any seasons, temperatures drastically change during day and night because it has a thin atmosphere, and it is the most heavily cratered planet.

Mercury doesn't have a moon, and since it is so close to the Sun, it will never have a moon.

Mercury is about twice as large as Pluto, and it would take 18 Mercury's to match Earth's size.

The first spacecraft to explore Mercury was NASA's Mariner 10, it happened in 1974.

If you were on Mercury, the Sun would appear three times as large in the sky as it does when viewed from Earth. The sunlight, however, would be seven times more powerful.

Mercury's core which pulled its surface inward due to contraction is believed to have reduced the planet's size between 1 - 7 km / 4 mi.

[1.] Wikipedia

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Mercury Facts for Kids | Fun & Interesting Information & History

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Mercury is the planet closest to our Sun, and it is the eighth largest of the nine planets. Click for even more facts and information for kids.

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https://www.esa.int/kids/en/learn/Our_Universe/Planets_and_moons/Mercury

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Mercury is the first planet from the Sun. It is not very easy to observe since it is always close to the Sun in the sky. Even when best placed, it is close to the horizon and only visible for a few hours after sunset or before sunrise.

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https://www.natgeokids.com/uk/discover/science/space/facts-about-the-earth/

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Earth, our wonderful world! But how much do you know about the planet we call home? Let's find out with our fascinating facts about the Earth...
Facts about the Earth

1) Earth is the third planet from the sun in our solar system. Its name comes from the the old English and Germanic words meaning 'the ground'.

2) Our amazing planet has been around for quite some time. By researching our planet's rocks, scientists have calculated the Earth to be around 4.5 billion years old!

3) Like all the planets, Earth orbits (travels around) around the sun. And it does so at some serious speed -- around 30 kilometres per second, in fact! It takes 365 days (one year) for the Earth to complete one full orbit.

4) Have you ever wondered why we have different seasons? We'll tell you -- it's because the Earth is tilted 23.4 degrees on its 'axis', an imaginary line straight through the middle of the planet form the North Pole to the South Pole. This means that different parts of the globe are tilted towards the sun at different times of the year (or at different times during its orbit).

5) Not only does Earth zoom through space, it also spins on its axis. The result? We have daytime and nighttime! As the planet rotates, the side facing the sun receives daylight and the the other is in darkness.

6) People often think of Earth as a gigantic sphere. But, in fact, its shape is more like a squished ball that bulges out at the equator -- an imaginary line around the middle of the planet, exactly between the North Pole and the South Pole.

7) This 'bulge' is caused by the Earth's spin and the effect of 'gravity'. Gravity is an invisible force that attracts objects towards each other. It's this force that pulls things towards the Earth and stops us floating off into space!

8) The Earth's diameter (distance straight through the middle) measures a huge 12,800 kilometres, making it the fifth largest planet in the solar system. Jupiter, Saturn, Uranus and Neptune are even bigger!

9) Earth is the only planet in our solar system known to support life. This is because it has two very important things that living creatures need to survive -- lots of oxygen and lots of water! Its distance from the sun means it's not too hot and not too cold for creatures to live on, too.

10) Earth's 'atmosphere' is also hugely important for sustaining life. The atmosphere is a huge blanket of gases - mostly oxygen and nitrogen - wrapped around Earth, protecting our planet from the sun's strong rays. At the same time, the atmosphere helps keep the Earth's temperature comfortable for living beings - and it protects us from meteors, too!

What did you think about our facts about the Earth? Leave a comment below and let us know!

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Facts about the Earth! | Science | National Geographic Kids

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Learn all about our amazing planet with our facts about the Earth! How big is Earth? Why do we have day and night, and four seasons? How old is the Earth?

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https://nineplanets.org/kids/earth/

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Earth Facts for Kids | Facts, Temperature, Habitation, Information & History

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Earth is the only planet whose English name does not derive from Greek or Roman mythology. Click for even more facts and information.

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https://www.natgeokids.com/uk/discover/science/space/facts-about-mars/

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Facts about Mars

1) Named after the Roman God of war, Mars is the fourth planet from the sun in our solar system.

2) Mars is also known as the ' Red Planet' because, well, it's red! This signature colour comes from the large amount of a chemical called iron oxide (or 'rust' as you might know it) in its rocks and soil.

3) Mars is the second smallest planet in the solar system after Mercury. With a diameter (distance through the middle) of 6,791 kilometres, it's roughly half the size of Earth.

4) It can get pretty cold on Mars -- much colder than our own planet, since it's further away from the sun. At the equator, temperatures can reach 20°C, but at its poles they can plummet to as low as -140°C. Brr!

5) Mars is home to the highest mountain in our solar system -- a volcano called Olympus Mons. Standing a whopping 24 kilometres high, it's about three times the height of Mount Everest!

Did you know...? There are bits of Mars here on Earth! In the past, asteroids hit the Red Planet, sending debris into space. Some of this debris landed on our planet as meteorites.

6) You could jump around three times higher on Mars than you can on Earth. Boing! This is because the planet's gravity - the force that keeps us on the ground - is much weaker.

7) Do you like to look at the at night? Well, check this out -- Mars has two moons! One is called Phobos and the other Deimos.

8) A day on Mars is 24 hours and 37 minutes -- only a little bit longer than a day on our own planet. A year on Mars, however, is almost twice as long, lasting 687 Earth days! This is because it takes a lot longer than Earth to complete its orbit around the Sun.

Did you know that we have a FREE downloadable Mars primary resource? Great for teachers, homeschoolers and parents alike!

9) Until recently, scientists believed that there was no liquid water on the surface of Mars -- only rocks, soil dust and ice. But... News flash! In 2018, they found evidence of a lake under the planet's south polar ice cap. Exciting stuff!

10) Humans have not yet been to Mars, but scientists have sent spacecraft there to help them research this fascinating planet. The first spacecraft to land on Mars were the Viking Landers, which touched down on the surface in 1976.

Want to learn more? Check out our facts about Earth, discover top Moon facts and learn about world-famous astronaut Neil Armstrong.

What did you think of our facts about Mars? Leave a comment below and let us know!

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Facts about Mars | Facts for kids - National Geographic Kids

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Learn all about the Red Planet in our fascinating facts about Mars. How big is Mars? What's the temperature on Mars? Is there water on Mars?

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https://nineplanets.org/kids/mars/

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Mars is named after the Roman god of war. For the Greeks, Mars was known as Ares. It was named after the god of war because of its red color.

Key Facts & Summary

Mars is the fourth planet from the Sun and the second-smallest planet of the Solar System.

Mars is the most widely searched planet for life, inspiring many works of fiction.

The first person to observe Mars with the use of a telescope was Galileo Galilei. He observed the Red Planet in 1610.

Mars is 227.9 million kilometers / 141.6 million miles away from the Sun.

Light from the Sun reaches Mars in about 13 minutes.

Mars is around two times smaller than Earth. It has a diameter of 6.779 km / 4.212 mi.

Mars is around 10 times less massive than Earth.

Mars is the outermost terrestrial planet, outside Earth's orbit. It is 50% farther away from the Sun than Earth.

Mars has two known natural satellites, Phobos and Deimos.

Phobos is predicted to suffer a collision with Mars in the distant future.

The atmosphere on Mars is thin, mostly comprised of carbon dioxide, nitrogen, and argon gases.

The tallest volcano/mountain in the Solar System is located on Mars. It is named Olympus Mons and it seems to have a height of 21 km / 13 mi.

Mars also has the biggest canyon in the Solar System. It is named Valles Marines. It is 4.000 km / 2.500 mi long and reaches depths of 7 km / 4 mi deep. The Grand Canyon on Earth is only 446 km / 226 mi long, and only 1.6 km / 1 mi deep.

Mars doesn't have a magnetic field however some areas are highly magnetized.

The average temperatures on Mars is -80 degrees Fahrenheit / -60 degrees Celsius.

Mars represents masculinity and the symbol of the planet is used for the male gender.

Mars is widely known as the Red planet. Its reddish appearance is caused by the presence of rusty iron in the ground. The name of the month March is derived from Mars.

Mars is visible to the naked eye, and as such, you can see it without the use of a telescope or binoculars. The Red planet is very similar to Earth, and scientists are trying to find out if life was present there.

Surface and Structure

In many ways, Mars can be considered Earth's brother. It has seasons, polar ice caps, volcanoes, canyons, and weather. There are many signs of ancient floods on the Red Planet, but now water mostly exists in icy dirt and thin clouds.

There is evidence of liquid salty water in the ground, especially on hillsides. This may be great if people will go there in the future, but observations continue.

Mars is the seventh-largest planet of the Solar System and the fourth planet from the Sun. It has the most varied and complex terrain than any of the terrestrial planets, except for Earth.

On Mars's surface, we have discovered the biggest mountain in the Solar System. It is named Olympus Mons, and it is three times bigger than the largest mountain on Earth, Everest.

Another great feature of Mars is Valles Marineris, a network of canyons that run 4.000 km / 2.485 mi long and stand from 2 to 7 km / 1 to 4 mi tall.

Hellas Planitia is a huge crater on Mars created from an ancient impact. It is located on the Red Planet's southern hemisphere and its over 6 km / 3.7 mi deep and 2.000 km / 1.242 mi across.

Oceans and lakes may have existed on Mars long ago, but it seems that water was only around for a short period. Some believe that water exists underneath Mars's surface.

There are many differences in Mars's southern and northern hemispheres. For example, in the southern hemisphere, many ancient cratered highlands are present, similar to the ones on the Moon.

In the northern hemisphere, plains have undergone changes since the planet formed long ago, and this hemisphere is also lower in elevation.

Time on Mars

A day on Mars is a little longer than a day on Earth. It lasts about 24.6 hours. A year on Mars, however, or the time that takes for the Red Planet to circle our Sun, lasts about 687 Earth days or almost twice as long as a year on Earth.

Fun Facts

1. Mars has seasons just like Earth, but they last longer. This is because it takes longer for it to orbit the Sun. The seasons vary in length since Mars has an egg-shaped orbit around the Sun.

2. The longest season on Mars is spring, which lasts for 194 days. Autumn is the shortest lasting only 142 days.

3. Occasionally, winds on Mars are strong enough to create dust storms. It takes months for all the dust to settle, and this is a great impediment for the space probes sent there.

4. Mars doesn't have a ring system like Saturn. However, one of its moons, Phobos, will crash on Mars in the distant future and this may create a ring system around the Red Planet.

5. Many observations and analyses indicate that Mars was once very similar to Earth, having water or even whole oceans.

6. If you stood on Mars and looked at the Sun, it would appear about half the size as we see it on Earth.

7. Pieces of Mars have fallen on Earth. Scientists are studying these materials to this day.

8. If you would weigh 100kg on Earth, on Mars you would weigh 38kg because Mars's gravity is only 38% that of Earth.

9. Around six Mars-sized planets would fit the volume of Earth. However, it would take 7 million Mars-sized planets to fill the volume of the Sun.

10. A book written by Jonathan Swift mentioned the two moons of Mars 151 years before they were actually discovered.

11. Some believe that the Valles Marines on Mars is the result of a huge collision.

Size and Comparison

Mars is and the second-smallest planet of the Solar System after Mercury, having a diameter of 6.779 km / 4.212 mi. It is 30% bigger than Mercury and almost two times smaller than Earth and Venus.

Neptune and Uranus have around 7.2 times the diameter of Mars. Saturn, on the other hand, has 17.1 times its diameter. But the biggest planet in the Solar System is Jupiter, and it has more than 20 times the diameter of Mars.

Trivia

Life on Mars

Throughout much of the 19 th century, it was believed that life on Mars existed partly due to a mistake. An astronomer believed that he observed straight lines on Mars' surface.

Many believed that this could only be the work of intelligent life as the straight lines resembled canals for irrigation purposes. However, as more advanced telescopes were built and observations on Mars's surface were more accurate - it was revealed that the straight lines were an optical illusion.

Mars and Venus atmosphere similarity

If Mars is among the most hospitable planets, Venus is among the most inhospitable. However, their atmosphere is similar in regards to one component - carbon dioxide - 95% for Mars, 97% for Venus.

However, the main difference is that Venus's greenhouse effect traps temperatures at around 480 degrees Celsius, while Mars doesn't exceed 20 degrees Celsius.

Other Characteristics

Mars has a thin but active atmosphere. The surface of the Red Planet isn't active, however, its volcanoes are dead. The atmosphere on Mars is made of carbon dioxide, nitrogen, and argon.

The planets closest to Mars, its neighbors, are Earth and Jupiter. Mars also has two moons, Phobos and Deimos. They are smaller than Earth's moon.

Phobos is slowly descending upon Mars, and scientists believe that one day it will crash on the Red Planet. Mars is the outermost terrestrial planet, almost 50% farther from the Sun than Earth.

Many missions were sent to Mars, so many that the Red Planet is theoretically populated with robots. Some projects here on Earth, want to colonize the Red Planet, beginning in 2022.

Mars Notes

Mars is a small planet, cold, and as far as we know, lifeless. However, it is the most hospitable planet in the Solar System, second only to Earth.

The first spacecraft to visit Mars was Mariner 4, this happened in 1965.

Mars has ice caps at both poles made up of solid carbon dioxide or dry ice.

Powerful dust storms and winds blow through the entire planet for months.

There are high chances that people will one day colonize the Red Planet.

Though Mars can become our second Earth, one of the biggest issues is gravity. The gravity on Mars can cause bone damage.

[2.] Wikipedia

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Mars Facts for Kids | Temperature, Surface & Information

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Mars is the god of War. In Greek mythology, he is known as Ares. The planet probably got this name due to its red color. Click for more kids facts.

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https://nineplanets.org/kids/jupiter/

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The planet Jupiter is named after the supreme Roman god. To the ancient Greeks, he was known as Zeus, ruler of the Greek gods, and Mount Olympus.

Key Facts & Summary

Jupiter is the fifth planet from the Sun and the biggest planet of our Solar System. Some consider it a failed star since it is made out of swirling gases and liquids such as 90% hydrogen, and 10% helium - very similar to the Sun.

Jupiter is the fourth brightest object in the sky and one of the five visible planets ( Mercury, Venus, Mars, Saturn ).

The envelope of gases - atmosphere - surrounding Jupiter is the largest planetary atmosphere in the Solar System. It makes up almost the entire planet. Basically, it doesn't have a true surface with its atmosphere reaching altitudes of 5.000 km / 1.864 mi.

Through the observations of Jupiter, the discovery of the four Galilean moons ended the belief that everything revolved around the Earth.

Jupiter has a total of 79 confirmed moons. It is second only to Saturn when it comes to the total amount of satellites.

Jupiter also has 3 ring systems but much smaller than Saturn's.

Though they can be seen only through ultraviolet, Jupiter's auroras are the brightest in the Solar System.

Jupiter has a mean radius of 69.911 kilometers / 43.440 miles, a diameter at the equator of around 142.984 km / 88.846 mi, and a diameter at the poles of 133.708 km / 83.082 mi.

Jupiter's mass is almost twice of all the Solar System's planets combined. It is 318 times more massive than Earth.

Jupiter is on average about 5.2 AU away from the Sun. One AU is equivalent to 150 million km / 93 million mi.

Jupiter experiences 200 times more asteroid and comet impacts than Earth.

In a way, Jupiter is the Solar System's vacuum cleaner, because of its powerful gravity which attracts many of the comets and asteroids to hit it rather than other planets.

Jupiter is the fifth planet from the Sun and the largest planet of the Solar System. It is more than twice as massive as all the other planets combined, being 318 times bigger than Earth.

The planet is very similar to a star, but it never got big enough to start burning. Jupiter has rings surrounding it, but they are very faint and hard to see.

It is the planet with the second-most moons, 79, after Saturn, who has 82. The closest planets to Jupiter are Mars and Saturn. The planet can be seen with the naked eye, you don't need a telescope or a pair of binoculars to see it.

Surface and Structure

Jupiter is a gas giant, just like Saturn. It is made mostly out of hydrogen and helium. It doesn't have a true surface, but it may have a solid core about the size of Earth at its center.

Jupiter is covered in swirling cloud stripes and has enormous storms like the Great Red Spot, which has been going on for hundreds of years.

The atmosphere is very thick, and it is made out of ammonia, sulfur, methane, and water vapor. Jupiter's atmosphere is the largest planetary atmosphere in the Solar System. It makes up almost the entire planet.

Time on Jupiter

A day on Jupiter goes by very fast. It only lasts for about 10 hours. However, since it is farther away from the Sun than Earth, one year on Jupiter - the time it takes for it to circle the Sun once - is equal to 11.8 Earth years.

Fun Facts

1. If Jupiter would be 75 times more massive than it currently is, it would become a star just like our Sun.

2. If you could somehow stand on Jupiter, and you would weigh 100 pounds on Earth, on Jupiter you would weigh 240 pounds due to the gravitational force. So basically, regardless of your weight, on Jupiter you would weigh 2.5 times more than on Earth.

3. We don't know how, but the ancient Babylonians wrote about Jupiter around 1.300 years ago. It may be the earliest recordings of the planet.

4. Because Jupiter spins very fast, probably the fastest out of all the planets, it is flattened a bit so it bulges at its equator.

5. The same speed gives power to Jupiter's strong magnetic field which is around 20 times stronger than Earth's. It is the most powerful magnetic field in the Solar System.

6. Jupiter is surrounded by dangerous waves of radiation, and this makes it hard for spacecraft to approach it.

7. The red spot on Jupiter was first seen in 1665 by an Italian astronomer named Giovanni Cassini.

8. If you could go down on Jupiter, the thin, cold atmosphere would become thicker and hotter until it turns into a thick, dark fog. The pressure further down is so great that the gases become liquid.

Size and Comparison

Jupiter has a mean radius of 69.911 kilometers / 43.440 miles, a diameter at the equator of around 142.984 km / 88.846 mi, and a diameter at the poles of 133.708 km / 83.082 mi. It is the biggest planet in the Solar System.

Compared to Earth, it has more than 11 times its diameter. Around 1.300 Earth's would fit inside Jupiter's volume. In comparison to Mercury, the smallest planet in the Solar System, it is more than 29 times its diameter. More than 24.462 Mercury's would fit inside Jupiter's volume.

Venus is similar to Earth in size, it has less than 11.8 times the diameter of Jupiter. Mars, on the other hand, has less than 20 times the diameter of Jupiter. Jupiter has around 2.8 times the diameter of Neptune and Uranus. In comparison to Saturn, it has 1.2 times its diameter.

Trivia

More Mass, Less Size?

Though Jupiter is 2.5 times more massive than all the planets of the Solar System combine, scientists predict that if it would get more mass, the giant would actually get smaller.

More mass will make the planet more dense, and this would cause it to start pulling it in on itself.

Is Jupiter a failed star?

Though some consider Jupiter a failed star, it doesn't have enough mass to trigger a fusion reaction in its core. That is the mechanism of how stars generate energy, by fusing hydrogen under extreme heat and pressure to create helium, releasing light and heat in the process.

This means that Jupiter has no way of becoming a star unless it would gain around 75 times more mass than it currently has.

Jupiter generates more heat than it receives from the Sun

Since it is the most massive planet in the Solar System, it is the closest to being a star, at least in terms of mass. Because of this mass, Jupiter generates high amounts of heat as it shrinks under gravity. It is unknown when Jupiter will stop shrinking.

Other Characteristics

The winds on Jupiter are very powerful. They are trapped in the planet's wide bands of latitude. Each of these bands has a slightly different chemical make-up and temperature.

Because of this, some of the bands have different colors. The light-colored bands are called "zones." The dark-colored bands are called "belts".

These clouds are different in color, depending on the altitude. Blue clouds are the lowest, followed by brown and white clouds. Red clouds are the highest.

The Great Red Spot is big enough to hold two Earths. It is a high-pressure region where clouds are much higher and colder than in the surrounding areas. Jupiter also has other spots, but they are far smaller.

Jupiter is very bright in the night sky, second only to Venus. The four most important moons of Jupiter, called the Galilean moons, are also quite visible, but you would need a pair of binoculars to see them.

One of the most important moons of Jupiter is Europa. This moon may have water on it, and it is currently closely studied. Another interesting moon of Jupiter is Io, which is the most volcanically active body in the Solar System.

Scientists believe that Jupiter was twice its current size when it was formed. The giant planet is constantly bombarded with asteroids and comets, almost 200 times more than Earth.

Jupiter Notes

Jupiter is the largest planet of the Solar System. It is the fifth planet from the Sun.

Jupiter is a gas giant, and it lacks a true surface. It is made up of about 90% hydrogen and 10% helium.

Jupiter has a faint ring system, and it is second in terms of the number of satellites only to Saturn. It has 79 moons, four of them, the Galilean moons, helped shape our view of the Universe.

Jupiter's moon Europa has many chances of developing life.

Jupiter shrinks 2 centimeters every year because it radiates too much heat.

[2.] Wikipedia

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Jupiter Facts for Kids | Fun & Interesting Information & History

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The planet Jupiter is named after the supreme Roman god. To the ancient Greeks, he was known as Zeus, ruler of the Greek gods, and Mount Olympus. Jupiter is the fifth planet from the Sun and the biggest planet of our Solar System.

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https://kids.nationalgeographic.com/space/article/mission-to-jupiter

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LOCATION: Fifth gas ball from the sun

DISTANCE FROM THE SUN: 460,237,112 to 507,040,015 miles (740,679,835 to 816,001,807 kilometers)

AVERAGE TEMPERATURE: -234° F (-148° C)

LENGTH OF SPACE JOURNEY FROM EARTH TO JUPITER: 13 months

GRAVITY: If you weigh 100 pounds (45 kilograms) on Earth, you'd weigh 253 pounds (115 kilograms) here.

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Mission to Jupiter - Get facts about this planet

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Get the facts on Jupiter, one of the largest planets.

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https://nineplanets.org/kids/saturn/

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The planet Saturn is named after the Roman god of agriculture. In Greek mythology, he is known as Cronus, the father of Zeus (Jupiter). Saturn is the root of the English word "Saturday."

Key Facts & Summary

Saturn is the sixth planet from the Sun with the largest planetary rings in the Solar System.

It is the second-largest planet in the Solar System after Jupiter.

Saturn has a radius of 58.232 kilometers / 36.183 miles and a diameter of 120.536 km / 74.897 mi.

The surface area of Saturn is 83 times greater than Earth.

Saturn is the King of the Moons, having a total of 82 confirmed moons. There are probably more out there.

The largest moon of Saturn is named Triton, and it is the second-largest moon in the Solar System after Jupiter's moon Ganymede. Triron is much bigger than even the planet Mercury.

Periodic storms are present on Saturn and they are large enough to be seen from Earth. They are named White Spots.

Saturn doesn't have a solid surface. It is enveloped by swirling gases and liquids the further down you go.

It is possible that Saturn may have a core, it would be at least twice the size of Earth and it would be comprised out of metals like iron, and nickel.

The temperature on Saturn's upper atmosphere is on average at around -175 degrees Celsius / -285 degrees Fahrenheit. This is quite cold for a gas giant at least. However, below its clouds, it gets considerably hotter.

Saturn is the most oblate planet in the Solar System. Its equatorial diameter is greater than the planet's polar diameter. If you look at Saturn through a telescope, it would appear flattened.

Saturn has the lowest density of all the planets. It is lighter than water and if placed on it, the planet would float.

The low density of Saturn is attributed to its composition. The planet is largely made up of gases such as hydrogen and helium.

Saturn's composition together with its atmosphere influences its color, giving it a brownish-yellow appearance.

Saturn is the sixth planet from the Sun and the second-largest planet in the Solar System after Jupiter. Saturn is the king of the moons because it has the most moons out of any planet, 82, and it may have even more.

Though it is the most distant of the visible planets - planets that can be seen without the need of a telescope or binoculars - a striking feature has always been noted, its rings.

Saturn is nicknamed the "Ringed Planet" - it has more than 30 ring systems around it. It isn't the only planet with rings, but it definitely has the most beautiful and visible ones.

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The first person to observe Saturn through a telescope was Galileo Galilei in the 1600s. Galileo wasn't sure of what he was seeing, and at first thought the planet had handles, and then he believed he observed three planets, when in fact, they were the rings of Saturn.

Structure and Composition

The rings of Saturn are made out of chunks of ice and rock. Their exact origin is unknown. These rings are very bright and are composed of many small particles that circle Saturn at their own speeds.

These objects range in size from a centime to several meters, and some few are kilometer-sized.

Saturn itself is mostly a ball of hydrogen and helium, and this is why it is known as a gas giant like Jupiter. Like Jupiter, Saturn has bands/clouds but much fainter, some of the spots in those bands are areas where big storms occur.

Time on Saturn

A day on Saturn goes by very fast. It takes only 10.7 hours for Saturn to spin once - a day. A year on Saturn is actually different because it is very far from the Sun.

Saturn circles the Sun once every 29 Earth years - thus one Saturnian year.

Fun Facts:

Galileo Galilei first observed Saturn in 1610, however, his telescope failed to observe the planet's rings. The discovery of the rings was made by Christiaan Huygens in 1659.

Out of the five visible planets ( Mercury, Venus, Mars, Jupiter ), Saturn is the most distant from Earth. It is around 10 times farther away from us than we are from the Sun.

Light takes about 1 hour and 29 minutes to travel from Saturn and then arrive at us.

The presence of ammonia gives Saturn a yellow appearance, ammonia hydrosulfide - orange, and water - white.

Since Saturn's axial tilt is similar to Earth, the southern and northern hemispheres are heated differently. Much of these variations in temperature are horizontal.

The rings of Saturn extend up to 282.000 km / 175.000 mi from the planet.

The particles that make up the rings of Saturn range from the size of small dust to as big a house, or even a mountain.

Saturn's ring system is divided into 7 groups: D ring, C ring, B ring, A ring, F ring, G ring, and E ring. Together, they are as wide as 4.5 Earths put side by side.

You could fit 764 Earths inside Saturn, and almost 1.600 Saturn's could fit into the Sun.

Some believe that the Great Flood that occurred on Earth was caused by a moment in time when Saturn and Jupiter came close to one another.

The winds on Saturn are the second fastest among the Solar System's planets, after Neptune's.

Size and Comparison

Saturn has a radius of 58.232 kilometers / 36.183 miles and a diameter of 120.536 km / 74.897 mi. It is the second-largest planet in the Solar System.

The biggest planet of the Solar System, Jupiter, has 1.2 times the diameter of Saturn. Satururn's diameter is around 10 times bigger than Earth's and Venus's.

It is more than two times bigger than Neptune and Uranus, but when it comes to Mars, it has 17.1 times its diameter. However, Mercury is the smallest planet, and Saturn has more than 23 times its diameter.

Trivia

The rings of Saturn will disappear

Scientists believe that Saturn will lose its rings in about 100 million years. The rings are pulled into Saturn by the planet's gravity as a dusty rain of ice.

These particles are also under the influence of Saturn's magnetic field and the event is often called Ring Rain.

The many names of Saturn

Many cultures across the world have given their own names to Saturn. In Greek, Saturn was known as Phainon while in Hindu astrology, it was known as Shani, a deity that judges the good and bad deeds done in life.

In the Chinese and Japanese cultures, Saturn was designated as the Earth Star.

Visitors of Saturn

Only four spacecraft have visited Saturn:

NASA's Pioneer 11 in 1979

NASA's twin Voyager 1 & 2 in 1980 and 1981

The international Cassini spacecraft in 2004.

The spacecraft Cassini studied Saturn for about 13 years. After it completed its mission, it was intentionally vaporized in Saturn's atmosphere in 2017.

The eeriest radio signals

Saturn has the eeriest radio emissions in the Solar System. The planet's sounds can be found and listened to on the internet, and they are indeed a bit disturbing.

Other Characteristics

Saturn has a thick atmosphere, but the pressure is so strong that it squeezes gas into a liquid. Winds are very powerful in the upper atmosphere and reach incredible speeds. In fact, they are the second fastest winds present on any planet.

Since it is primarily made out of gases and liquid, Saturn isn't very dense. If you could put Saturn on water, it would float. The closest planets to Saturn are Jupiter and Uranus.

The planet is bright enough that it can be seen without a telescope or a pair of binoculars, but if you look at it through a telescope, it will appear squished since its made out of gas and liquid and it spins very quickly.

Saturn's outer moons are also visible through the use of a telescope. The planet has recently gained the title of King of the Moons since now 82 moons have been confirmed. Before this, it was Jupiter who was king.

Though life cannot exist on Saturn because it doesn't have a surface, its moons Titan and Enceladus have internal oceans. They could possibly hold life. Some missions are planned to visit those moons soon.

Scientists believe that Saturn will lose its rings in about 100 million years.

Saturn Notes

1. Saturn is a gas giant primarily made out of gases and liquid. It doesn't have a surface.

2. Saturn is the planet with the most moons, 82, and the planet with the most beautiful ring systems.

3. Saturn was known to the ancients, some of them considered Saturn as bein a star rather than a planet.

4. Saturn is the sixth planet from the Sun and the second-largest.

5. Some of the spacecraft that visited Saturn are Pioneer 11, Cassini, and Voyager 1 and 2.

6. The materials that makeup Saturn are lighter than water, and as such, if you would place Saturn in a pond, it would float.

[1.] Wikipedia

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Saturn Facts for Kids | Interesting, Fun, Information & History

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The planet Saturn is named after the Roman god of agriculture. In Greek mythology, he is known as Cronus, the father of Zeus (Jupiter). Saturn is the root of the English word "Saturday." Saturn is the sixth planet from the Sun with the largest planetary rings in the Solar System.

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https://space-facts.com/saturn/

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Best known for its fabulous ring system, Saturn is the sixth planet from the Sun and the second largest in our solar system. Like Jupiter, Saturn is a gas giant and is composed of similar gasses including hydrogen, helium and methane.

Facts about Saturn

Saturn is the most distant planet that can be seen with the naked eye.
It is the fifth brightest object in the solar system and is also easily studied through binoculars or a small telescope.

Saturn was known to the ancients, including the Babylonians and Far Eastern observers.
It is named for the Roman god Saturnus, and was known to the Greeks as Cronus.

Saturn is the flattest planet.
Its polar diameter is 90% of its equatorial diameter, this is due to its low density and fast rotation. Saturn turns on its axis once every 10 hours and 34 minutes giving it the second-shortest day of any of the solar system's planets.

Saturn orbits the Sun once every 29.4 Earth years.
Its slow movement against the backdrop of stars earned it the nickname of "Lubadsagush" from the ancient Assyrians. The name means "oldest of the old".

Saturn's upper atmosphere is divided into bands of clouds.
The top layers are mostly ammonia ice. Below them, the clouds are largely water ice. Below are layers of cold hydrogen and sulfur ice mixtures.

Saturn has oval-shaped storms similar to Jupiter's.
The region around its north pole has a hexagonal-shaped pattern of clouds. Scientists think this may be a wave pattern in the upper clouds. The planet also has a vortex over its south pole that resembles a hurricane-like storm.

Saturn is made mostly of hydrogen.
It exists in layers that get denser farther into the planet. Eventually, deep inside, the hydrogen becomes metallic. At the core lies a hot interior.

Saturn has the most extensive rings in the solar system.
The Saturnian rings are made mostly of chunks of ice and small amounts of carbonaceous dust. The rings stretch out more than 120,700 km from the planet, but are amazingly thin: only about 20 meters thick.

Saturn has 150 moons and smaller moonlets.
All are frozen worlds. The largest moons are Titan and Rhea. Enceladus appears to have an ocean below its frozen surface.

Titan is a moon with complex and dense nitrogen-rich atmosphere.
It is composed mostly of water ice and rock. Its frozen surface has lakes of liquid methane and landscapes covered with frozen nitrogen. Planetary scientists consider Titan to be a possible harbour for life, but not Earth-like life.

Four spacecraft have visited Saturn.
Pioneer 11, Voyager 1 and 2, and the Cassini-Huygens mission have all studied the planet. Cassini orbited Saturn from July 2004 until September 2017, sending back a wealth of data about the planet, its moons, and rings.

Saturn has more moons than any other planet.
20 new moons were discovered in 2019 bring the total to 82, 3 more than Jupiter.

Saturn Diagrams

Saturn size compared to Earth

Saturn distance from the Sun and orbital eccentricity

Saturn's Rings

While all the gas giants in our solar system have rings none of them are as extensive or distinctive as Saturn's. The rings were discovered by Galileo Galilei 1610 who observed them with a telescope. The first 'up close' view of the rings were by Pioneer 11 spacecraft which flew by Saturn on September 1, 1971.

Saturn's rings are made up of are billions of particles that range in size from tiny dust grains to objects as large as mountains. These are made up of chunks of ice and rock, believed to have come from asteroids comets or even moons, that broke apart before they reached the planet.

Saturn's rings are divided into 7 groups, named alphabetically in the order of their discovery (Outwards from Saturn; D, C, B, A, F, G and E). The F ring is kept in place by two of Saturn's moons, Prometheus and Pandora, these are referred to as 'shepherd moons'. Other satellites are responsible for creating divisions in the rings as well as shepherding them.

Saturn's Atmosphere

Saturn's atmosphere is composed primarily of hydrogen (96%) and helium (3%) with traces of other substances like methane, ammonia, acetylene, ethane, propane and phosphine. Winds in the upper atmosphere can reach speeds of 500 metres a second, these combined with heat rising from within the planet's interior cause yellow and gold bands.

Sources: https://solarsystem.nasa.gov/planets/saturn/overview/, https://nssdc.gsfc.nasa.gov/planetary/factsheet/saturnfact.html
First Published: June 2012
Last Updated: April 2020
Author: Chris Jones

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Saturn Facts 🪐 - Interesting Facts about Planet Saturn

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Best known for its fabulous ring system, Saturn is the sixth planet from the Sun and the second largest in our solar system. Like Jupiter,

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https://nineplanets.org/kids/uranus/

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The planet Uranus is named after the ancient Greek God of the heavens, the earliest supreme god. He was the father of Cronus / Saturn, which in turn, was the father of Zeus / Jupiter.

Key Facts & Summary

Uranus is the seventh planet from the Sun, and the third-largest planet in the Solar System It is the biggest of the ice giants.

Uranus is 2.9 billion kilometers / 1.8 billion miles away from the Sun.

Uranus has a radius of 25.362 km / 15.759 mi, and a diameter of 51.118 km or 31.763 mi.

It comparison to Earth's mass, Uranus has around 14.5 times the mass of Earth. It has the fourth-largest mass in the Solar System.

Uranus rotates in the opposite direction than most planets, from East to West. It is also the only planet known to rotate on its side.

Uranus has the coldest planetary atmosphere in the Solar System. Temperatures are on average at around -224 degrees Celsius / -371 degrees Fahrenheit.

Both Uranus and Neptune share similar compositions. Their chemical compositions differ from the other gas giants Jupiter and Saturn. Because of this, Uranus and Neptune are classified as ice giants rather than gas giants, for easier distinction.

Uranus has a similar atmosphere to Jupiter and Saturn in its primary composition of hydrogen and helium. However, it contains more "ices" such as water, ammonia, methane, and traces of other hydrocarbons.

Uranus has 13 known rings surrounding it but they are difficult to observe.

The reason why Uranus is blue is due to the presence of methane.

Uranus has 27 moons orbiting it. There may be more, all of them are very small.

The biggest moon of Uranus is Titania. It is the eighth largest moon in the Solar System.

Uranus has been visited only once by a spacecraft, namely, Voyager 2.

Another moon of Uranus, Miranda, is one of the strangest objects in the Solar System. It has a very deformed landscape with strange and hard to explain patters.

Uranus is the seventh planet from the Sun and the third largest of all the planets in our Solar System. Both Uranus and Neptune are considered ice giants due to their different compositions from the other gas giants Jupiter and Saturn.

Both Uranus and Neptune are blue because they have methane. Uranus is larger in size than Neptune but it is smaller in weight. It has thirteen ring systems and 23 confirmed moons.

Structure and Composition

Every gas giant lacks the presence of a surface. Uranus is made of water, methane, and ammonia fluids above a small rocky center. The thick atmosphere is made of hydrogen and helium like Jupiter and Saturn.

The rings of Uranus can be summarized into two sections. The inner rings and the outer rings. The inner rings are narrow and very faint. The outer rings are brightly colored and easier to see.

The clouds on Uranus are difficult to see ,but they are present. Some of these clouds were observed ,and they revealed huge storms as big as the United States.

Some of the wind speeds recorded on Uranus were among the most powerful ever witnessed in the Solar System.

Time on Uranus

Uranus has a shorter day than Earth. One day only lasts 17 hours. One year on Uranus, or the time it takes for it to circle the Sun once, it the equivalent of 84 Earth years. Having to wait for a birthday cake for 84 years is no fun!

Fun Facts:

1. The biggest moons of Uranus, all of them, have surface areas smaller than the continent of Australia.

2. The rings of Uranus are thought to have formed around 600 million years ago from the collision of moons or other big celestial objects.

3. The rings of Uranus are unique since they are dark and extremely narrow.

4. The intensity of light on Uranus is about 1/400 of that on Earth.

5. In good conditions, Uranus can be seen without binoculars.

6. Umbriel, one of the biggest moons of Uranus, has a very dark surface. It consists mainly of ice and only a fraction of rock.

7. William Herschel, the discoverer of Uranus, first believed that the planet was a comet. However, years later it was confirmed to be a planet.

8. The original name proposed for Uranus was Georgian Sidus - which means Georgian Planet, in honor of King George II, however, the scientific community didn't agree. In a way, we are thankful for that even now.

9. Uranus has a very unusual axial tilt. Many believe that this was caused by a collision with an Earth-sized planet.

10. Uranus is the lightest out of all the four gas giants.

11. The Uranian moons are named for characters created by Alexander Pope and William Shakespeare.

Size and Comparison

Uranus has a radius of 25.362 km / 15.759 mi and a diameter of 51.118 km or 31.763 mi. It is the third-largest planet in the Solar System and the biggest of the ice giants.

Uranus is slightly larger than Neptune, however, it is smaller in mass. In comparison to Earth, Uranus has four times its diameter. When it comes to volume, 63 Earths could fit inside Uranus.

Both Neptune and Uranus have 10 times the diameter of Mercury, the smallest planet in the Solar System. Jupiter, the largest planet in the Solar System, has 2.8 times the diameter of Uranus.

Trivia

A name for a planet, a name for an element

The common tradition after naming a new planet is to name a newly discovered element after the planet, a sort of variant. In the case of Uranus, the chemical element Uranium, discovered in 1789, was named after the newly discovered planet.

The first planet discovered

Uranus is the first planet discovered in modern history. The planet was too dim to be seen by ancient civilizations and as such it remained hidden in the darkness of the sky.

Other Characteristics

Uranus is probably the coldest planet of the Solar System for reasons not yet understood. Something prevents the heat from Uranus's core from reaching the surface.

Uranus is the only planet in the Solar System that spins on its side. It is believed that this was caused by a collision in the distant past. Like Venus, Uranus also spins in the opposite direction than the other planets of the Solar System.

The closest planets to Uranus, its neighbors, are Neptune and Saturn. Uranus has many moons, 27, and they were named after characters from fictional books.

Uranus was discovered in 1781 by William Herschel, a British astronomer. The planet was visited only once, by the spacecraft Voyager 2, in 1986.

Uranus is sometimes visible in the sky. You won't need binoculars or a telescope to see it, but you can only view it on a very clear night sky. Even with binoculars, it would be easy to spot the planet.

Uranus Notes

Uranus is a gas giant like Neptune, Saturn, and Jupiter. However, since it has a different composition, both Uranus and Neptune are termed, ice giants.

Uranus is the coldest planet of the Solar System and the only planet which spins on its side. It also spins in the opposite direction of most planets.

Uranus has 27 moons, but there may be more out there, hidden in its thirteen ring systems.

Though Uranus may seem peaceful, it does have violent storms, and since it doesn't have a surface, life wouldn't be able to develop there.

Uranus is 20 times further away from the Sun than Earth.

In 2033, Uranus will complete its third orbit/year around the Sun since its discovery in 1781.

Uranus has a bluish appearance due to the presence of methane, a type of gas. This is also why Neptune appears blue.

It isn't known what prevents Uranus's heat from the core to reach its surface.

[1.] Wikipedia

Image sources:

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Uranus Facts for Kids | Rotation, Information, Summary & History

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Uranus has a very unique rotation-it spins on its side at an almost 90-degree angle, unlike other planets. Click for more interesting facts & information.

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https://kids.nationalgeographic.com/space/article/mission-to-uranus

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Mission to Uranus - Get facts about this planet

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Get the facts on Uranus, a planet with a sideways axis.

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https://nineplanets.org/kids/neptune/

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The planet Neptune is named after the Roman god of the sea. In Greek mythology, he is known as Poseidon. The planet was probably given this name due to its blue appearance.

Key Facts & Summary

Neptune is the farthest planet from the Sun at an average distance of 4.5 billion kilometers / 2.8 billion miles.

Neptune is the fourth-largest planet in the Solar System and the smallest of the gas giants.

Both Neptune and Uranus are termed ice giants since they have different compositions than Saturn and Jupiter.

Neptune has a radius of 24.764 km / 15.387 mi, and a diameter of 49.244 km / 30.598 mi.

The core of Neptune is about 1.5 times the size of Earth.

Wind speeds on Neptune are among the fastest recorded in the Solar System. Some may reach up to 2.160 km / 1.324 mi per hour. They are five times stronger than the strongest winds on Earth.

Neptune's average surface temperatures are around -214 degrees Celsius / -353 degrees Fahrenheit.

Neptune has a total of 6 ring systems surrounding it. Some of them contain ring arcs or clusters of dust particles.

Neptune also has 14 moons. The largest moon of Neptune is Triton, and it is the seventh-largest known moon of any planet. Some believe that the moon is actually a captured dwarf planet.

Neptune's color is believed to be influenced by the presence of methane in its atmosphere, but there is also an unknown factor contributing to this.

Neptune is the first planet to be discovered by the use of mathematical calculations and predictions.

Uranus is Neptune's near twin in size and composition.

Neptune has a powerful magnetic field. It is 27 times stronger than Earth's.

Neptune formed around 4.5 billion years ago however, many believe that it was closer to the Sun then than now, but the planet started to drift away.

Neptune is the farthest planet from the Sun, and the fourth largest out of all the planets of the Solar System. It is more than 30 times farther from the Sun than Earth.

Though it is far, it is not the coldest planet, that title belongs to Uranus. However, Neptune is very cold, nonetheless. It is a dark and windy planet, having the most powerful winds in the Solar System.

The reason why Neptune is blue is due to the presence of a specific gas named methane. This is also why the planet Uranus is also blue. Both Uranus and Neptune are known as ice giants due to their compositions.

Surface and Structure

The atmosphere of Neptune is made out of hydrogen, helium, and methane. The planet is basically a thick fog of water, ammonia, and methane over an Earth-sized solid center.

Like other gas giants, Neptune has a ring system, six of them to be exact, but they are faint. Neptune also has 14 confirmed moons. The weather on Neptune is very active. Sometimes dark spots form in the atmosphere, which are basically storms the size of Earth.

It has the wildest and strangest weather out of all the planets in the Solar System. The winds speeds on Neptune are the most outstanding.

Some winds have been able to reach up to 2,160 km / 1.324 mi per hour. They are nearly a supersonic flow. These winds break the sound barrier being 5 times stronger than the strongest winds on Earth.

Time on Neptune

A day on Neptune is less than a day on Earth. It lasts for only 16 hours. Since Neptune is the farthest planet from the Sun, it has a very long journey to complete around it. One year on Neptune is equal to 165 Earth years.

Fun Facts

1. Neptune was given the name of the Roman god of the sea due to its bluish-ocean like color. All of Neptune's moons have been named after water deities in response.

2. Until the orbit of Pluto was understood, and its status dropped from that of a planet to a dwarf planet, Neptune was considered the second farthest planet from the Sun.

3. Neptune was observed in 1613 by Galileo Galilei but he thought that he observed a star and failed to find it again.

4. Scientists believe that Neptune formed around 4.5 billion years ago, and it began to drift away from the Sun around 4 billion years ago.

5. Light from Neptune reaches us in around 4 hours.

6. Deep inside Neptune's lower regions, there is a hot, dense fluid sometimes called a water-ammonia ocean. Though it is hot, many simply refer to it as icy.

7. Some believe that inside Neptune's lowest regions, conditions are such that even methane decomposes into diamond crystals that rain downwards.

8. Neptune has the wildest and strangest weather in the Solar System. However, it is not understood how it gets so much energy to produce such weather.

Size and Comparison

Neptune has a radius of 24.764 km / 15.387 mi, and a diameter of 49.244 km / 30.598 mi. Though it is Uranus's twin in many ways, it is the smaller of the pair but denser.

Uranus is 103% bigger than Neptune, being only slightly larger with a couple of hundred km/mi. In comparison to gas giants, things get serious.

Saturn has 2.3 times the diameter of Neptune, while Jupiter, the largest planet in the Solar System, has 2.8 times Neptune's diameter. When it comes to the terrestrial planets, Neptune is four times larger than Earth and Venus. It has 7.2 times the diameter of Mars, and more than 10 times the diameter of Mercury, the smallest planet.

Trivia

Neptune or Uranus?

The name Neptune was first given to the seventh discovered planet of the Solar System. However, the name was discarded but Uranus ultimately led to the discovery of the eighth planet, which would bear the name Neptune.

So maybe in another dimension, this decision wasn't discarded and Uranus would have been named Neptune, and Neptune would have been named Uranus.

Other names for Neptune

Most languages use some variant of the name "Neptune" for the planet. In Chinese, Vietnamese, Japanese and Korean, the planet's name was translated as "sea king star" while in Mongolian it is called Dalain Van.

In modern Greek, the planet's name is Poseidon while in Māori the planet is called Tangaroa, the name of the Māori god of the sea.

The discovery of Neptune

Neptune is invisible to the unaided eye and thus it evaded discovery for centuries, until in 1846 when the works of Le Verrier and Johann Galle found the bluish planet.

Uranus was the greatest factor in the discovery of Neptune. Astronomers were calculating the orbit of Uranus and observed that the planet wasn't following their models.

This forced astronomers to conclude that another undiscovered planet might be the reason behind the perturbations. Le Verrier predicted where this mysterious planet should be, and Johann Galle found it one degree away from the predicted point. This makes Neptune the first planet ever to be discovered by the use of mathematical calculations and predictions.

Other Characteristics

Neptune is the only planet that isn't visible to the naked eye. Only with instruments such as telescopes you can see it. Since Neptune is the eighth and most distant planet from the Sun, its only neighbor is Uranus.

The blue planet was discovered in 1846 by Urbain Le Verrier, John Couch Adams, and Johann Galle by the use of mathematical predictions.

One of the largest moons of Neptune is Triton. Triton is even bigger than the dwarf planet Pluto, and some scientists believe that the moon is also a dwarf planet, captured by Neptune's gravity. Triton is the seventh-largest moon in the Solar System.

Neptune Notes

Neptune is the eighth planet from the Sun, and the fourth largest.

It is an ice giant that has the strongest winds of any planet in the Solar System. The presence of methane gives Neptune its bluish color.

Though Neptune is the farthest planet from the Sun, it isn't the coldest. The coldest planet is Uranus.

Neptune has 6 known planetary rings and only 14 confirmed moons. One of them, namely Triton, is believed to be a captured dwarf planet.

If you stood on Neptune, the Sun would appear 900 times fainter in the sky. If you could fit Earth inside Neptune, you would need 58 Earth's to do so.

Voyager 2 is the only spacecraft to have reached Neptune to this day.

Neptune has no surface since it is basically a swirling world of gases and liquid, surrounding a core. Life wouldn't be possible to exist there, at least the way we know it.

[1.] Wikipedia

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Neptune Facts for Kids | Temperature, Surface & Information

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Neptune's blue color is the result of a gas called "methane" in its atmosphere. Click for even more interesting kid friendly facts. Browse today.

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https://kids.nationalgeographic.com/space/article/mission-to-neptune

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LOCATION: Last gas ball from the sun

DISTANCE FROM THE SUN: 2,771,162,074 to 2,819,185,846 miles (4,459,753,056 to 4,537,039,826 kilometers)

AVERAGE TEMPERATURE: -353° F (-214° C)

LENGTH OF SPACE JOURNEY FROM EARTH TO NEPTUNE: 12 years

GRAVITY: If you weigh 100 pounds (45 kilograms) on Earth, you'd weigh 114 pounds (52 kilograms) here.

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Mission to Neptune - Get facts about this planet

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Get the facts on Neptune, the last gas giant in our solar system.

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https://kids.nationalgeographic.com/space/article/mission-to-saturn

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LOCATION: Sixth gas ball from the sun

DISTANCE FROM THE SUN: 838,741,509 to 934,237,322 miles (1,349,823,615 to 1,503,509,229 kilometers)

AVERAGE TEMPERATURE: -288° F (-178° C)

LENGTH OF SPACE JOURNEY FROM EARTH TO SATURN: 3 years

GRAVITY: If you weigh 100 pounds (45 kilograms) on Earth, you'd weigh 107 pounds (49 kilograms) here.

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Mission to Saturn - Get facts about this planet

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Get the facts on Saturn, the planet famous for its rings.

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https://kids.kiddle.co/Neptune

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Quick facts for kidsNeptune

Discovery

Discovered by
Urbain Le Verrier
John Couch Adams
Johann Galle

Discovery date

September 23, 1846

Designations

Adjectives

Neptunian

Orbital characteristics

Epoch J2000

Aphelion

4,553,946,490 km
30.44125206 AU

Perihelion

4,452,940,833 km
29.76607095 AU

4,503,443,661 km
30.10366151 AU

Eccentricity

0.011214269

60,190 days
164.79 years
89,666 Neptune solar days

Inclination

1.767975° to Ecliptic
6.43° to Sun's equator
0.72° to Invariable plane

Known satellites
13

Physical characteristics

24,622±19 km

Flattening

0.0171 ± 0.0013

7.6408×10 ⁹ km²
14.98 Earths

Volume

6.254×10 ¹³ km³
57.74 Earths

Mass

1.0243×10 ²⁶ kg
17.147 Earths

11.15 m/s²
1.14g

0.6713 day
16 h 6 min 36 s

Equatorial rotation velocity

2.68 km/s
9,660 km/h

19 h 57 m 20 s

Albedo

0.290 ( bond)
0.41 ( geom.)

Surface temp.

min

mean

max

1 bar level

72 K

0.1 bar (10 kPa)

55 K

2.2″-2.4″

Atmosphere

Composition by volume

Neptune, is the eighth and last planet from the Sun in the Solar System. It is a gas giant. It is the fourth largest planet and third heaviest. Neptune has four rings which are hard to see from the Earth. It is 17 times heavier than Earth and is a little bit heavier than Uranus. It was named after the Roman God of the Sea.

Neptune's atmosphere is mostly made up of hydrogen and helium. It also contains small amounts of methane which makes the planet appear blue. Neptune's blue color is much brighter compared to Uranus', which has a similar amount of methane, so there might be another reason why Neptune is blue. Neptune also has the strongest winds of any planet in the solar system, measured as high as 2,100 km/h or 1,300 mph.

Neptune was discovered by the astronomers, Urbain Le Verrier and John Couch Adams. They were both honored for the discovery. The planet was the first to be discovered by mathematical calculations instead of using a telescope. Because of Uranus' odd movements in its orbit (the line which a planet follows in moving), it made astronomers search for the new planet. The planet was visited by only one spacecraft, on August 25, 1989. Neptune once had a huge storm known as the "Great Dark Spot" which was discovered in 1989 by Voyager 2. However, the dark spot was not seen in 1994, and new spots were found since then. It is not known why the dark spot disappeared. Visits by more space probes have been proposed.

In 1821, Alexis Bouvard published the astronomical tables of the orbit of Uranus. Later observations showed that Uranus was moving in an irregular way in its orbit, making some astronomers think of another large body being the cause of the irregular motions of Uranus. In 1843, John Couch Adams calculated the orbit of an eighth planet that would possibly be influencing the orbit of Uranus. He sent his calculations to Sir George Airy, the Astronomer Royal, who asked Adams for an explanation. Adams began to make a copy of the reply, but never sent it.

In 1846, Urbain Le Verrier, who was not working with Adams, made his own calculations but also failed to get much attention from French astronomers. However, in the same year, John Herschel began to support the mathematical method and encouraged James Challis to search for the planet. After much delay, Challis began his unwilling search in July 1846. Meanwhile, Le Verrier had convinced Johann Gottfried Galle to search for the planet.

After the news of the discovery of Neptune spread, there was also a lot of arguing between the French and the British about who was to be deserved credit for the discovery. Later, an international agreement decided that both Le Verrier and Adams together deserved credit. However, historians are now reviewing the topic after the rediscovery in 1998 of the "Neptune papers" (historical documents from the Royal Greenwich Observatory), which had seemingly been stolen by astronomer Olin Eggen for nearly three decades and were only rediscovered (in his ownership) right after his death. After reviewing the documents, some historians now think that Adams does not deserve equal credit with Le Verrier.

Shortly after its discovery, Neptune was temporarily called "the planet exterior to Uranus" or "Le Verrier's planet". The first suggestion for a name came from Galle. He proposed the name . In England, Challis suggested the name . In France, Arago suggested that the new planet be called Leverrier, a suggestion which was met with a lot of opposition outside France. French almanacs promptly reintroduced the name Herschel for Uranus and Leverrier for the new planet.

Meanwhile, on separate and different reason, Adams suggested changing the name Georgian to Uranus, while Leverrier (through the Board of Longitude) suggested Neptune for the new planet. Struve gave support of that name on December 29, 1846, to the Saint Petersburg Academy of Sciences. Soon Neptune was internationally agreed among many people and was then the official name for the new planet. In Roman mythology, Neptune was the god of the sea, identified with the Greek god, Poseidon.

Mass and composition

At 10.243×10 ²⁵ kg, Neptune's mass puts the planet between Earth and the largest gas giants; Neptune has seventeen Earth masses but just 1/18th the mass of Jupiter. Neptune and Uranus are often considered to be part of a sub-class of gas giant known as " ice giants", given their smaller size and big differences in composition compared to Jupiter and Saturn. In the search for extrasolar planets, Neptune has been used as a reference to determine the size and structure of the discovered planet. Some discovered planets that have similar masses like Neptune are often called "Neptunes". just as astronomers refer to various extra-solar "Jupiters."

The atmosphere of Neptune is made up mostly of hydrogen, with a smaller amount of helium. A tiny amount of methane is also detected in the atmosphere. Important absorption bands of methane happen at wavelengths above 600 nm, in the red and infrared portion of the spectrum. This absorption of red light by the atmospheric methane gives Neptune its blue hue.

Because Neptune orbits so far from the Sun, it gets very little heat with the uppermost regions of the atmosphere at −218 °C (55 K). Deeper inside the layers of gas, however, the temperature rises slowly. Like Uranus, the source of this heating is unknown, but the differences are larger: Neptune is the farthest planet from the Sun, yet its internal energy is strong enough to create the fastest winds seen in the Solar System. Several possible explanations have been suggested, including radiogenic heating from the planet's core, the continued radiation into space of leftover heat made by infalling matter during the planet's birth, and gravity waves breaking above the tropopause.

Weather and magnetic field

In 1989, the Great Dark Spot, a cyclonic storm system the size of Eurasia, was discovered by NASA's spacecraft. The storm resembled the Great Red Spot of Jupiter. However, on November 2, 1994, the Hubble Space Telescope did not see the Great Dark Spot on the planet. Instead, a new storm similar to the Great Dark Spot was found in the planet's northern hemisphere. The reason why the Great Dark Spot has disappeared is unknown. One possible theory is that heat transfer from the planet's core disrupted the atmospheric balance and existing circulation patterns. The Scooter is another storm, a white cloud group farther south than the Great Dark Spot. Its nickname was given when it was first noticed in the months leading up to the Voyager encounter in 1989: it moved faster than the Great Dark Spot. Later images showed clouds that moved even faster than Scooter. The Wizard's eye/ Dark Spot 2 is another southern cyclonic storm, the second most strongest storm seen during the 1989 encounter. It originally was completely dark, but as Voyager came closer to the planet, a bright core developed and is seen in most of the highest resolution images.

Unlike other gas giants, Neptune's atmosphere shows the presence of high clouds making shadows on a thick cloud deck below. Though Neptune's atmosphere is much more active than that of Uranus, both planets are made up of the same gases and ices. Uranus and Neptune are not exactly the same type of gas giants like to Jupiter and Saturn, but are rather ice giants, meaning they have a larger solid core and are also made of ices. Neptune is very cold, with temperatures as low as −224 °C (−372 °F or 49 K) recorded at the cloud tops in 1989.

Neptune's Rings

Very small blue colored rings have been discovered around the blue planet, but they are not as well known as the rings of Saturn. When these rings were discovered by a team led by Edward Guinan, originally they thought that the rings may not be complete rings. However, this was proven wrong by Voyager 2. Neptune's planetary rings have a weird "clumpy" arrangement. Although the cause is currently unknown but some scientists think that it may be because of the gravitational contact with small moons that orbit near them.

Proof that the rings are incomplete first began in the mid-1980s, when stellar occultation were found to rarely show an extra "blink" just before or after the planet occulted the star. Pictures from Voyager 2 in 1989 solved the problem, when the ring system was found to have several faint rings. The farthest ring, Adams, has three famous arcs now named Liberté, Egalité, and Fraternité (Liberty, Equality, and Fraternity).

The existence of arcs is very hard to understand because the laws of motion would predict that arcs spread out into a single ring in a very short time. The gravitational effects of Galatea, a moon just inward from the ring, are now thought to have created the arcs.

Several other rings were discovered by the Voyager cameras. Also with the thin Adams Ring about 63,000 km from the center of Neptune, the Leverrier Ring is at 53,000 km and the wider, smaller Galle Ring is at 42,000 km. A very small outward expansion to the Leverrier Ring has been named Lassell; it is surrounded at its outer edge by the Arago Ring at 57,000 km.

New Earth-based observations published in 2005 appeared to show that Neptune's rings are a lot more unstable than thought before. To be exact, it looks like that the Liberté ring might disappear maybe quickly in less than 100 years. The new observations seems to puzzle our understanding of Neptune's rings into a lot of confusion.

Neptune has 14 known moons. Triton is the largest Neptunian moon, comprising more than 99.5% of the mass in orbit around Neptune, and it is the only one massive enough to be spheroidal. Triton was discovered by William Lassell just 17 days after the discovery of Neptune itself. Unlike all other large planetary moons in the Solar System, Triton has a retrograde orbit, indicating that it was captured rather than forming in place; it was probably once a dwarf planet in the Kuiper belt. It is close enough to Neptune to be locked into a synchronous rotation, and it is slowly spiralling inward because of tidal acceleration. It will eventually be torn apart, in about 3.6 billion years, when it reaches the Roche limit. In 1989, Triton was the coldest object that had yet been measured in the Solar System, with estimated temperatures of 38 K (−235 °C).

From July to September 1989, Voyager 2 discovered six moons of Neptune. Of these, the irregularly shaped Proteus is notable for being as large as a body of its density can be without being pulled into a spherical shape by its own gravity. Although the second-most-massive Neptunian moon, it is only 0.25% the mass of Triton. Neptune's innermost four moons- Naiad, Thalassa, Despina and Galatea-orbit close enough to be within Neptune's rings. The next-farthest out, Larissa, was originally discovered in 1981 when it had occulted a star. This occultation had been attributed to ring arcs, but when Voyager 2 observed Neptune in 1989, Larissa was found to have caused it. Five new irregular moons discovered between 2002 and 2003 were announced in 2004. A new moon and the smallest yet, Neptune XIV, was found in 2013. Because Neptune was the Roman god of the sea, Neptune's moons have been named after lesser sea gods.
Neptune's largest moon - Triton
Observation

Neptune cannot be seen with naked eye alone, since Neptune's normal brightness are between magnitudes +7.7 and +8.0, which can be out-shined by Jupiter's Galilean moons, the dwarf planet Ceres, and the asteroids 4 Vesta, 2 Pallas, 7 Iris, 3 Juno and 6 Hebe. A telescope or strong binoculars will show Neptune as a small blue dot, similar in appearance to Uranus. The blue color comes from the methane in its atmosphere. Its small obvious size has made it difficult to study visually; most telescopic data was quite limited until the arrival of the Hubble Space Telescope and large ground-based telescopes with adaptive optics.

Exploration

is the only spacecraft that has visited Neptune. The spacecraft's closest approach to the planet occurred on 25 August 1989. Because this was the last major planet the spacecraft could visit, it was decided to make a close flyby of the moon Triton, regardless of the consequences to the trajectory, similarly to what was done for 's encounter with Saturn and its moon Titan. The images relayed back to Earth from Voyager 2 became the basis of a 1989 PBS all-night program, Neptune All Night.

During the encounter, signals from the spacecraft required 246 minutes to reach Earth. Hence, for the most part, Voyager 2's mission relied on preloaded commands for the Neptune encounter. The spacecraft performed a near-encounter with the moon Nereid before it came within 4,400 km of Neptune's atmosphere on 25 August, then passed close to the planet's largest moon Triton later the same day.

The spacecraft verified the existence of a magnetic field surrounding the planet and discovered that the field was offset from the centre and tilted in a manner similar to the field around Uranus. Neptune's rotation period was determined using measurements of radio emissions and Voyager 2 also showed that Neptune had a surprisingly active weather system. Six new moons were discovered, and the planet was shown to have more than one ring.

The flyby also provided the first accurate measurement of Neptune's mass which was found to be 0.5 percent less than previously calculated. The new figure disproved the hypothesis that an undiscovered Planet X acted upon the orbits of Neptune and Uranus.

After the Voyager 2 flyby mission, the next step in scientific exploration of the Neptunian system, is considered to be a Flagship orbital mission. Such a hypothetical mission is envisioned to be possible in the late 2020s or early 2030s. However, there have been discussions to launch Neptune missions sooner. In 2003, there was a proposal in NASA's "Vision Missions Studies" for a "Neptune Orbiter with Probes" mission that does Cassini-level science. Another, more recent proposal was for Argo, a flyby spacecraft to be launched in 2019, that would visit Jupiter, Saturn, Neptune, and a Kuiper belt object. The focus would be on Neptune and its largest moon Triton to be investigated around 2029. The proposed New Horizons 2 mission (which was later scrapped) might also have done a close flyby of the Neptunian system.

Images for kids

Four images taken a few hours apart with the NASA/ESA Hubble Space Telescope's Wide Field Camera 3. Near infrared radiation data has been used as red channel.

In 2018, the European Southern Observatory developed unique laser-based methods to get clear and high-resolution images of Neptune from the surface of Earth.

The Great Dark Spot in a color-uncalibrated image by Voyager 2.

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Quick facts for kidsNeptune Discovery Discovered by Urbain Le Verrier John Couch Adams Johann Galle Discovery date September 23, 1846 Designations Adjectives Neptunian Orbital characteristics Epoch J2000 Aphelion 4,553,946,490 km 30.44125206 AU Perihelion 4,452,940,833 km 29.76607095 AU 4,503,443,661 km 30.10366151 AU Eccentricity 0.011214269 60,190 days 164.79 years 89,666 Neptune solar

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Quick facts for kidsSaturn

Designations

Adjectives

Saturnian

Orbital characteristics

Epoch J2000

Aphelion

1,513,325,783 km
10.115 958 04 AU

Perihelion

1,353,572,956 km
9.048 076 35 AU

1,433,449,370 km
9.582 017 20 AU

Eccentricity

0.055 723 219

10,832.327 days
29.657 296 yr

Inclination

2.485 240° to Ecliptic
5.51° to Sun's equator
0.93° to Invariable plane

Known satellites

around 200 observed (61 with secure orbits)

Physical characteristics

58,232±6 km

Flattening

0.097 96 ± 0.000 18

4.27×10 ¹⁰ km ²
83.703 Earths

Volume

8.2713×10 ¹⁴ km ³
763.59 Earths

Mass

5.6846×10 ²⁶ kg
95.152 Earths

0.687 g/cm ³
(less than water)

10,44 m/s²
0.914g

0.439-0.449 days
(10 h 32 - 47 min)

Equatorial rotation velocity

9.87 km/s
35 500 km/h

2 h 42 min 21 s
40.589°

Albedo

0.342 bond
0.47 geom

Surface temp.

min

mean

max

1 bar level

134 K

0.1 bar

84 K

14.5" - 20.1"
(excludes rings)

Atmosphere

Composition by volume

~96% hydrogen (H ₂)
Ices:
ammonia
water
ammonium hydrosulfide (NH ₄ SH)

Saturn is the sixth planet from the Sun in the Solar System. It is the second largest planet in the Solar System, after Jupiter. Like Jupiter, Uranus and Neptune, it is a " gas giant".

Inside Saturn is probably a core of iron, nickel, silicon and oxygen compounds, surrounded by a deep layer of metallic hydrogen, then a layer of liquid hydrogen and liquid helium and finally, an outer gaseous layer.

Saturn has 62 known moons orbiting the planet; 53 are officially named. The largest moon is Titan, which is larger in volume than the planet Mercury. Titan is the second-largest moon in the Solar System. The largest moon is Jupiter's moon, Ganymede. There is also a very large system of rings around Saturn. These rings are made of ice with smaller amounts of rocks and dust. Saturn is about 1,400,000,000 km (869,000,000 mi) from the Sun. Saturn takes 29.6 years on Earth to revolve around the Sun.

Saturn was named after the Roman god Saturnus (called Kronos in Greek mythology). Saturn's symbol is ♄ which is the symbol of Saturnus' sickle.

Physical features

Saturn is an oblate spheroid, meaning that it is flattened at the poles, and it swells out around its equator. The planet's equatorial diameter is 120,536 km (74,898 mi), while its polar diameter (the distance from the north pole to the south pole) is 108,728 km (67,560 mi); a 9% difference. Saturn has a flattened shape; it is due to its very fast rotation, rotating once every 10.8 hours. Saturn is the only planet in the Solar System that is less dense than water. Even though the planet's core is very dense, it has a gaseous atmosphere, so the average specific density of the planet is 0.69 g/cm ³ (less than the density of water). This means if Saturn could be placed in a large pool of water, it would float.

Atmosphere

The outer part of Saturn's atmosphere is made up of about 96% hydrogen, 3% helium, 0.4% methane and 0.01% ammonia. There are also very small amounts of acetylene, ethane and phosphine.

Saturn's clouds show a banded pattern, like the cloud bands seen on Jupiter. Saturn's clouds are much fainter and the bands are wider at the equator. Saturn's lowest cloud layer is made up of water ice, and is about 10 km (6 mi) thick. The temperature here is quite low, at 250 K (-10° F, -23° C). However scientists do not agree about this. The layer above, about 77 km (48 mi) thick, is made up of ammonium hydrosulfide ice, and above that is a layer of ammonia ice clouds 80 km (50 mi) thick. The highest layer is made up of hydrogen and helium gases, which extends between 200 km (124 mi) and 270 km (168 mi) above the water cloud tops. Auroras are also known to form in Saturn in the mesosphere. The temperature at Saturn's cloud tops is extremely low, at 98 K (-283°F, -175°C). The temperatures in the inner layers are much higher than the outside layers because of the heat produced by Saturn's interior. Saturn's winds are some of the fastest in the Solar System, reaching 1,800 km/h (1,118 mph), ten times faster than winds on Earth.

Storms and spots

Saturn's atmosphere is also known to form oval shaped clouds, similar to the clearer spots seen in Jupiter. These oval spots are cyclonic storms, the same as cyclones seen on Earth. In 1990, the Hubble Space Telescope found a very large white cloud near Saturn's equator. Storms like the one in 1990 were known as Great White Spots. These unique storms only exist for a short time and only happen about every 30 Earth years, at the time of the summer solstice in the Northern Hemisphere. Great White Spots were also found in 1876, 1903, 1933, and 1960. If this cycle continues, another storm will form in about 2020.

The Voyager 1 spacecraft found a hexagonal cloud pattern near Saturn's north pole at about 78°N. The Cassini−Huygens probe later confirmed it in 2006. Unlike the north pole, the south pole does not show any hexagonal cloud feature. The probe also discovered a hurricane-like storm locked to the south pole that clearly showed an eyewall. Until this discovery, eyewalls had only been seen on Earth.

Saturn's interior is similar to Jupiter's interior. It has a small rocky core about the size of the Earth at its centre. It is very hot; its temperature reaches 15,000 K (26,540 °F (14,727 °C)). Saturn is so hot that it gives out more heat energy into space than it receives from the Sun. Above it is a thicker layer of metallic hydrogen, about 30,000 km (18,641 mi) deep. Above that layer is a region of liquid hydrogen and helium. The core is heavy, with about 9 to 22 times more mass than the Earth's core.

Magnetic field

Saturn has a natural magnetic field that is weaker than Jupiter's. Like the Earth's, Saturn's field is a magnetic dipole. Saturn's field is unique in that it is perfectly symmetrical, unlike any other known planet. This means the field is exactly in line with the planet's axis. Saturn generates radio waves, but they are too weak to be detected from Earth. The moon Titan orbits in the outer part of Saturn's magnetic field and gives out plasma to the field from the ionised particles in Titan's atmosphere.

Rotation and orbit

Saturn's average distance from the Sun is over 1,400,000,000 km (869,000,000 mi), about nine times the distance from the Earth to the Sun. It takes 10,759 days, or about 29.7 years, for Saturn to orbit around the Sun. This is known as Saturn's orbital period.

Voyager 1 measured Saturn's rotation as being 10 hours 14 minutes at the equator, 10 hours 40 minutes closer to the poles, and 10 hours 39 minutes 24 seconds for the planet's interior. This is known as its rotational period.

Cassini measured the rotation of Saturn as being 10 hours 45 minutes 45 seconds ± 36 seconds. That is about six minutes, or one percent, longer than the radio rotational period measured by the Voyager 1 and Voyager 2 spacecraft, which flew by Saturn in 1980 and 1981.

Saturn's rotational period is calculated by the rotation speed of radio waves released by the planet. The Cassini−Huygens spacecraft discovered that the radio waves slowed down, suggesting that the rotational period increased. Since the scientists do not think Saturn's rotation is actually slowing down, the explanation may lie in the magnetic field that causes the radio waves.

Planetary rings

Saturn is best known for its planetary rings which are easy to see with a telescope. There are seven named rings; A, B, C, D, E, F, and G rings. They were named in the order they were discovered, which is different to their order from the planet. From the planet the rings are: D, C, B, A, F, G and E.

Scientists believe that the rings are the material left after a moon broke apart. A new idea says that it was a very large moon, most of which crashed into the planet. This left a large amount of ice to form the rings, and also some of the moons, like Enceladus, which are thought to be made of ice.

The rings were first discovered by Galileo Galilei in 1610, using his telescope. They did not look like rings to Galileo, so he called them "handles". He thought that Saturn was three separate planets that almost touched one another. In 1612, when the rings were facing edge on with the Earth, the rings disappeared, then reappeared again in 1613, further confusing Galileo. In 1655, Christiaan Huygens was the first person to recognise Saturn was surrounded by rings. Using a much more powerful telescope than Galilei's, he noted Saturn "is surrounded by a thin, flat, ring, nowhere touching...". In 1675, Giovanni Domenico Cassini discovered that the planet's rings were in fact made of smaller ringlets with gaps. The largest ring gap was later named the Cassini Division. In 1859, James Clerk Maxwell showed that the rings cannot be solid, but are made of small particles, each orbiting Saturn on their own, otherwise, it would become unstable or break apart. James Keeler studied the rings using a spectroscope in 1895 which proved Maxwell's theory.

Physical features

The rings range from 6,630 km (4,120 mi) to 120,700 km (75,000 mi) above the planet's equator. As proved by Maxwell, even though the rings appear to be solid and unbroken when viewed from above, the rings are made of small particles of rock and ice. They are only about 10 m (33 ft) thick; made of silica rock, iron oxide and ice particles. The smallest particles are only specks of dust while the largest are the size of a house. The C and D rings also seem to have a "wave" in them, like waves in water. These large waves are 500 m (1,640 ft) high, but only moving slowly at about 250 m (820 ft) each day. Some scientists believe that the wave is caused by Saturn's moons. Another idea is the waves were made by a comet hitting Saturn in 1983 or 1984.

The largest gaps in the rings are the Cassini Division and the Encke Division, both visible from the Earth. The Cassini Division is the largest, measuring 4,800 km (2,983 mi) wide. However, when the Voyager spacecrafts visited Saturn in 1980, they discovered that the rings are a complex structure, made out of thousands of thin gaps and ringlets. Scientists believe this is caused by the gravitational force of some of Saturn's moons. The tiny moon Pan orbits inside Saturn's rings, creating a gap within the rings. Other ringlets keep their structure due to the gravitational force of shepherd satellites, such as Prometheus and Pandora. Other gaps form due to the gravitational force of a large moon farther away. The moon Mimas is responsible for clearing away the Cassini gap.

Recent data from the Cassini spacecraft has shown that the rings have their own atmosphere, free from the planet's atmosphere. The rings' atmosphere is made of oxygen gas, and it is produced when the Sun's ultraviolet light breaks up the water ice in the rings. Chemical reaction also occurs between the ultraviolet light and the water molecules, creating hydrogen gas. The oxygen and hydrogen atmospheres around the rings are very widely spaced. As well as oxygen and hydrogen gas, the rings have a thin atmosphere made of hydroxide. This anion was discovered by the Hubble Space Telescope.

The Voyager space probe discovered features shaped like rays, called spokes. These were also seen later by the Hubble telescope. The Cassini probe photographed the spokes in 2005. They are seen as dark when under sunlight, and appear light when against the unlit side. At first it was thought the spokes were made of microscopic dust particles but new evidence shows that they are made of ice. They rotate at the same time with the planet's magnetosphere, therefore, it is believed that they have a connection with electromagnetism. However, what causes the spokes to form is still unknown. They appear to be seasonal, disappearing during solstice and appearing again during equinox.

Saturn has 53 named moons, and another nine which are still being studied. Many of the moons are very small: 33 are less than 10 km (6 mi) in diameter and 13 moons are less than 50 km (31 mi). Seven moons are large enough to be a near perfect sphere caused by their own gravitation. These moons are Titan, Rhea, Iapetus, Dione, Tethys, Enceladus and Mimas. Titan is the largest moon, larger than the planet Mercury, and it is the only moon in the Solar System to have a thick, dense atmosphere. Hyperion and Phoebe are the next largest moons, larger than 200 km (124 mi) in diameter.

In December 2004 and January 2005 a man-made satellite called the Cassini−Huygens probe took lots of close photos of Titan. One part of this satellite, known as the Huygens probe, then landed on Titan. Named after the Dutch astronomer Christiaan Huygens, it was the first spacecraft to land in the outer Solar System. The probe was designed to float in case it landed in liquid. Enceladus, the sixth largest moon, is about 500 km (311 mi) in diameter. It is one of the few outer solar system objects that shows volcanic activity. In 2011, scientists discovered an electric link between Saturn and Enceladus. This is caused by ionised particles from volcanos on the small moon interacting with Saturn's magnetic fields. Similar interactions cause the northern lights on Earth.

Exploration

Saturn was first explored by the Pioneer 11 spacecraft in September 1979. It flew as close as 20,000 km (12,427 mi) above the planet's cloud tops. It took photographs of the planet and a few of its moons, but were low in resolution (the quality was not very good). It discovered a new, thin ring called the F ring. It also discovered that the dark ring gaps appear bright when viewed towards the Sun, which shows the gaps are not empty of material. The spacecraft measured the temperature of the moon Titan.

In November 1980, Voyager 1 visited Saturn, and took higher resolution photographs of the planet, rings and moons. These photos were able to show the surface features of the moons. Voyager 1 went close to Titan, and gained much information about its atmosphere. In August, 1981, Voyager 2 continued to study the planet. Photos taken by the space probe showed that changes were happening to the rings and atmosphere. The Voyager spacecrafts discovered a number of moons orbiting close to Saturn's rings, as well as discovering new ring gaps.

On July 1, 2004, the Cassini−Huygens probe entered into orbit around Saturn. Before then, it flew close to Phoebe, taking very high resolution photos of its surface and collecting data. On December 25, 2004, the Huygens probe separated from the Cassini probe before moving down towards Titan's surface and landed there on January 14, 2005. It landed on a dry surface, but it found that large bodies of liquid exist on the moon. The Cassini probe continued to collect data from Titan and a number of the icy moons. It found evidence that the moon Enceladus had water erupting from its geysers. Cassini also proved, in July 2006, that Titan had hydrocarbon lakes, located near its north pole. In March 2007, it discovered a large hydrocarbon lake the size of the Caspian Sea near its north pole.

Cassini observed lightning occurring in Saturn since early 2005. The power of the lightning was measured to be 1,000 times more powerful than lightning on Earth. Astronomers believe that the lightning observed in Saturn is the strongest ever seen.

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Images for kids

Methane bands circle Saturn. The moon Dione hangs below the rings to the right.

Possible beginning of a new moon (white dot) of Saturn (image taken by Cassini on 15 April 2013)

Galileo Galilei observed the rings of Saturn in 1610, but was unable to determine what they were

Saturn eclipses the Sun, as seen from Cassini. The rings are visible, including the F Ring.

In Spanish: Saturno (planeta) para niños

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The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. It is mostly made up of molecular hydrogen and helium. It is also made up of methane, ammonia, hydrogen sulfide, water, nitrogen, sulfur, and noble gases.

Images for kids

Vertical structure of the atmosphere of Jupiter. Note that the temperature drops together with altitude above the tropopause. The Galileo atmospheric probe stopped transmitting at a depth of 132 km below the 1 bar "surface" of Jupiter.

Zones, belts and vortices on Jupiter. The wide equatorial zone is visible in the center surrounded by two dark equatorial belts (SEB and NEB). The large grayish-blue irregular "hot spots" at the northern edge of the white Equatorial Zone change over the course of time as they march eastward across the planet. The Great Red Spot is at the southern margin of the SEB. Strings of small storms rotate around northern-hemisphere ovals. Small, very bright features, possible lightning storms, appear quickly and randomly in turbulent regions. The smallest features visible at the equator are about 600 kilometers across. This 14-frame animation spans 24 Jovian days, or about 10 Earth days. The passage of time is accelerated by a factor of 600,000. The occasional black spots in the image are moons of Jupiter getting into the field of view.

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The atmosphere of Jupiter is the largest planetary atmosphere in the Solar System. It is mostly made up of molecular hydrogen and helium. It is also made up of methane, ammonia, hydrogen sulfide, water, nitrogen, sulfur, and noble gases. Vertical structure of the atmosphere of Jupiter.

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The atmosphere of Mars is the layer of gases surrounding Mars. It is mainly made up of carbon dioxide. The average atmospheric pressure of the Martian surface (6.0 mbar) is much lower than that of the Earth (1,013 mbar). The pressure is well below the Armstrong limit, meaning that water boils at the normal temperature of the human body: 98.6 °F (36.6 °C).

The Martian atmosphere contains 96% carbon dioxide, 1.9% argon, 1.9% nitrogen, and traces of oxygen, carbon monoxide, water and methane, and so on. Ever since the discovery of methane in 2003, scientists say that this might indicate life. It has also been suggested that is may be caused by geochemical processes, volcanic or hydrothermal activity.

The atmosphere of Mars is quite dusty, giving the Martian sky a light brown or orange-red color when seen from the surface. Data from NASA pointed out that the dust particles are 1.5 micrometres diameter.

On 18 March 2015, NASA found an aurora that is not fully understood and an unexplained dust cloud in the atmosphere of Mars.

Liquid water on Mars was once commonplace, which means the atmosphere was thicker. Many studies have found that the atmosphere of Mars has been weakened over time due to solar winds. On Earth, the magnetic field protects us from most of the wind. Mars used to have a magnetic field, but cooling of the core has resulted in the magnetic field being lost.

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In Spanish: Atmósfera de Marte para niños

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The atmosphere is the layer of gases around the Earth. It is held in place by Earth's gravity. It is made up mainly of nitrogen (78.1%). It also has plentiful oxygen (20.9%) and small amounts of argon (0.9%), carbon dioxide (~ 0.035%), water vapor, and other gases. The atmosphere protects life on Earth by absorbing (taking) ultraviolet rays from the sun. It makes our days cooler and our nights warmer.

Solid particulates, including ash, dust, volcanic ash, etc. are small parts of atmosphere. They are important in making clouds and fog.

The atmosphere does not end at a specific place. The higher above the Earth, the thinner the atmosphere. There is no clear border between the atmosphere and outer space, though the Kármán line is sometimes treated as a border. Even higher, for some purposes the edge of the magnetosphere is treated as a border. 75% of the atmosphere is within 11 kilometres (6.8 miles) of the Earth's surface.

History of Earth's atmosphere

Originally, the Earth's atmosphere had almost no free oxygen.

1. The first atmosphere consisted of gases in the solar nebula, mainly hydrogen. There might also have been simple hydrides such as those now found in the gas giants (Jupiter and Saturn): water vapor, methane and ammonia.

2. The atmosphere gradually changed to mostly carbon dioxide and nitrogen. The lighter gases, like hydrogen and helium, cannot be held by the Earth's gravity, and would escape. For a long time (say two billion years or more), the atmosphere was dominated by carbon dioxide.

3. In the Great Oxygenation Event the atmosphere changed to the kind we have now, with oxygen replacing the carbon dioxide. Our atmosphere is still mostly nitrogen, but most living organisms interact more with oxygen than with nitrogen. Oxygenation began with cyanobacteria making free oxygen by photosynthesis. Most organisms today need oxygen for their respiration: only a few anaerobic organisms can grow without oxygen.

Temperature and the atmospheric layers

Some parts of the atmosphere are hot or cold, depending on height. Starting from the surface and climbing straight up, the air gets colder in the troposphere, but then it becomes hotter, higher in the stratosphere. These changes of temperature are divided into layers. These are like layers of an onion. The difference between the layers is the way the temperature changes.

These are the layers of the atmosphere, starting from the ground:

Troposphere - Starts at the ground. Ends somewhere between 0 to 18 kilometres (0 to 11 miles). The higher, the colder. Weather in this layer affects our daily life.

Stratosphere - Starts at 18 kilometres (11 miles). Ends at 50 kilometres (31 miles). The higher, the hotter. The heat comes from the Ozone layer at the top of the stratosphere. There is little water vapor and other substances in this layer. Airplanes fly in this layer because it is usually stable and air resistance is small.

Mesosphere - Starts at 50 kilometres (31 miles). Ends at 80 or 85 kilometres (50 or 53 miles). The higher, the colder. Winds in this layer are strong, so the temperature is not stable.

Thermosphere - Starts at 80 or 85 kilometres (50 or 53 miles). Ends at 640 kilometres (400 miles) or higher. The higher, the hotter. This layer is very important in radio communication because it helps to reflect some radio waves.

Exosphere - Above the thermosphere. This is the top layer, and merges into interplanetary space.

Where one layer changes to the next have been named "-pauses." So the tropopause is where the troposphere ends (7 to 14 kilometres (4.3 to 8.7 miles) high). The stratopause is at the end of the stratosphere. The mesopause is at the end of the mesosphere. These are called boundaries.

The average temperature of the atmosphere at the surface of Earth is 14 °C (57 °F).

The atmosphere has pressure. This is because even though air is a gas, it has weight. The average atmospheric pressure at sea level is about 101.4 kilopascals (14.71 psi).

Density and mass

The density of air at sea level is about 1.2 kilograms per cubic meter. This density becomes less at higher altitudes at the same rate that pressure becomes less. The total mass of the atmosphere is about 5.1 × 10 ¹⁸ kg, which is only a very small part of the Earth's total mass.

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Images for kids

2009 NASA photo showing Earth's atmosphere at sunset, with Earth silhouetted

Blue light is scattered more than other wavelengths by the gases in the atmosphere, surrounding Earth in a visibly blue layer when seen from space on board the ISS at an altitude of 335 km (208 mi).

Space Shuttle Endeavour orbiting in the thermosphere. Because of the angle of the photo, it appears to straddle the stratosphere and mesosphere that actually lie more than 250 km (160 mi) below. The orange layer is the troposphere, which gives way to the whitish stratosphere and then the blue mesosphere.

Temperature trends in two thick layers of the atmosphere as measured between January 1979 and December 2005 by microwave sounding units and advanced microwave sounding units on NOAA weather satellites. The instruments record microwaves emitted from oxygen molecules in the atmosphere. Source:

In Spanish: Atmósfera terrestre para niños

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