# data[].attributes.attachment_link.description
Planet Neptune Overview Dark, cold and whipped by supersonic winds, giant Neptune is the eighth and most distant major planet orbiting our Sun. More than 30 times as far from the Sun as Earth, Neptune is not visible to the naked eye. In 2011, Neptune completed its first 165-year orbit since its discovery.

# data[].attributes.attachment_link.readable_text
Mercury is the closest planet to the sun and also the smallest planet in the solar system.

The small and cratered planet does not have any moons and zips around the sun faster than any other planet in the solar system, hence why the Romans named it after their swift-footed messenger god.

It is the second densest planet after Earth, with a huge metallic core roughly 2,200 to 2,400 miles (3,600 to 3,800 kilometers) wide, or about 75% of the planet's diameter. In comparison, Mercury's outer shell is only 300 to 400 miles (500 to 600 km) thick. The combination of its massive core and composition, which includes an abundance of volatile elements, has left scientists puzzled for years.

The Sumerians also knew of Mercury at least 5,000 years ago. It was often associated with Nabu, the god of writing, according to a site connected to NASA's MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) mission.

Mercury was also given separate names for its appearance as both a morning star and an evening star. Greek astronomers knew, however, that the two names referred to the same body, and Heraclitus, around 500 B.C., correctly thought that both Mercury and Venus orbited the sun, not Earth.

How hot is Mercury?

Because the planet is so close to the sun, Mercury's surface temperature can reach a scorching 840 degrees Fahrenheit (450 degrees Celsius). However, since this world doesn't have much of a real atmosphere to entrap any heat, at night temperatures can plummet to minus 275 degrees Fahrenheit (minus degrees 170 Celsius), a temperature swing of more than 1,100 degrees Fahrenheit (600 degrees Celsius), the greatest in the solar system.

How big is Mercury?

Mercury is the smallest planet in the solar system - it is only slightly larger than Earth's moon. Since it has no significant atmosphere to stop impacts, the planet is pockmarked with craters. About 4 billion years ago, an asteroid roughly 60 miles (100 km) wide struck Mercury with an impact equal to 1 trillion 1-megaton bombs, creating a vast impact crater roughly 960 miles (1,550 km) wide. Known as the Caloris Basin, this crater could hold the entire state of Texas. Another large impact may have helped create the planet's odd spin, according to research in 2011.

Mercury surface characteristics

As close to the sun as Mercury is, in 2012, NASA's MESSENGER spacecraft discovered water ice in the craters around its north pole, where regions may be permanently shaded from the heat of the sun. The southern pole may also contain icy pockets, but MESSENGER's orbit did not allow scientists to probe the area. Comets or meteorites may have delivered ice there, or water vapor may have outgassed from the planet's interior and frozen out at the poles.

(Image credit: NASA/Bill Ingalls)

Average distance from the sun: 35,983,095 miles (57,909,175 km). By comparison: 0.38 Earth's distance from the sun

Perihelion (closest approach to sun): 28,580,000 miles (46,000,000 km). By comparison: 0.313 times that of Earth

Aphelion (farthest distance from sun): 43,380,000 miles (69,820,000 km). By comparison: 0.459 times that of Earth

Day length: 58.646 Earth days

Color: Gray

As if Mercury isn't small enough, it not only shrank in its past but is continuing to shrink today, according to a 2016 report. The tiny planet is made up of a single continental plate over a cooling iron core. As the core cools, it solidifies, reducing the planet's volume and causing it to shrink. The process crumpled the surface, creating lobe-shaped scarps or cliffs, some hundreds of miles long and soaring up to a mile high, as well as Mercury's "Great Valley," which at about 620 miles long, 250 miles wide and two miles deep (1,000 by 400 by 3.2 km) is larger than Arizona's famous Grand Canyon and deeper than the Great Rift Valley in East Africa.

"The young age of the small scarps means that Mercury joins Earth as a tectonically active planet with new faults likely forming today as Mercury's interior continues to cool and the planet contracts," Tom Watters, Smithsonian senior scientist at the National Air and Space Museum in Washington, D.C., said in a NASA statement.

Indeed, a 2016 study of cliffs on Mercury's surface suggested the planet may still rumble with earthquakes, or "Mercuryquakes." In addition, in the past, Mercury's surface was constantly reshaped by volcanic activity. However, another 2016 study suggested Mercury's volcano eruptions likely ended about 3.5 billion years ago.

One 2016 study suggested that Mercury's surface features can generally be divided into two groups - one consisting of older material that melted at higher pressures at the core-mantle boundary, and the other of newer material that formed closer to Mercury's surface. Another 2016 study found that the dark hue of Mercury's surface is due to carbon. This carbon wasn't deposited by impacting comets, as some researchers suspected - instead, it may be a remnant of the planet's primordial crust.

Mercury's magnetic field

A completely unexpected discovery made by Mariner 10 was that Mercury possessed a magnetic field. Planets theoretically generate magnetic fields only if they spin quickly and possess a molten core. But Mercury takes 59 days to rotate and is so small - just roughly one-third Earth's size - that its core should have cooled off long ago.

"We had figured out how the Earth works, and Mercury is another terrestrial, rocky planet with an iron core, so we thought it would work the same way," Christopher Russell, a professor at the University of California, Los Angeles, said in a University of California, Los Angeles statement.

An unusual interior could help to explain the differences in Mercury's magnetic field when compared to Earth. Observations from MESSENGER revealed that the planet's magnetic field is approximately three times stronger in its northern hemisphere than in its southern. Russell co-authored a model that suggests that Mercury's iron core may be turning from liquid to solid at the core's outer boundary rather than the inner.

"It's like a snow storm in which the snow formed at the top of the cloud and middle of the cloud and the bottom of the cloud too," said Russell. "Our study of Mercury's magnetic field indicates iron is snowing throughout this fluid that is powering Mercury's magnetic field."

The discovery in 2007 by Earth-based radar observations that Mercury's core may still be molten could help explain its magnetism, though the solar wind may play a role in dampening the planet's magnetic field.

Although Mercury's magnetic field is just 1% the strength of Earth's, it is very active. The magnetic field in the solar wind - the charged particles streaming off the sun - periodically touches upon Mercury's field, creating powerful magnetic tornadoes that channel the fast, hot plasma of the solar wind down to the planet's surface.

Does Mercury have an atmosphere?

Instead of a substantial atmosphere, Mercury possesses an ultra-thin "exosphere" made up of atoms blasted off its surface by solar radiation, the solar wind and micrometeoroid impacts. These quickly escape into space, forming a tail of particles, according to NASA.

The atmosphere of Mercury is a "surface-bound exosphere, essentially a vacuum." It contains 42% oxygen, 29% sodium, 22% hydrogen, 6% helium, 0.5% potassium, with possible trace amounts of argon, carbon dioxide, water, nitrogen, xenon, krypton and neon, according to NASA.

Mercury's orbit

Mercury speeds around the sun every 88 Earth days, traveling through space at nearly 112,000 mph (180,000 km/h), faster than any other planet. Its oval-shaped orbit is highly elliptical, taking Mercury as close as 29 million miles (47 million km) and as far as 43 million miles (70 million km) from the sun. If one could stand on Mercury when it is nearest to the sun, it would appear more than three times as large as it does when viewed from Earth.

(Image credit: Karl Tate, SPACE.com)

Oddly, due to Mercury's highly elliptical orbit and the 59 Earth-days or so it takes to rotate on its axis, when on the scorching surface of the planet, the sun appears to rise briefly, set, and rise again before it travels westward across the sky. At sunset, the sun appears to set, rise again briefly, and then set again.

In 2016, a rare transit of Mercury happened, where the planet crossed the face of the sun as seen from Earth. Mercury's transit may have yielded secrets about its thin atmosphere, assisted in the hunt for worlds around other stars, and helped NASA hone some of its instruments.

As Mercury takes just Earth days to orbit the sun and Earth takes 365 days, approximately three or four times a year Mercury overtakes Earth during its trip around the sun and an optical illusion occurs, according to The New York Times. Mercury appears to move "backward" across the sky for about three weeks, it is during this time Mercury is said to be in retrograde. Astrologers consider Mercury in retrograde to be a time of misfortune and miscommunication as the perceived backward motion interferes with the planet's rules, according to Dictionary.com. The retrograde motion is explained in this YouTube video from Vox.

Mercury Q&A with an expert

We asked Larry Nittler, a cosmochemist who studies the origin and evolution of the solar system at Arizona State University, some questions about Mercury.

What are some of the most fascinating aspects of this planet?

What surprising things about Mercury have we discovered recently?

Mercury missions and research

The first spacecraft to visit Mercury was Mariner 10, which imaged about 45% of the surface and detected its magnetic field.

NASA's MESSENGER orbiter was the second spacecraft to visit Mercury. When it arrived in March 2011, it became the first spacecraft to orbit the planet. The mission came to an abrupt end on April 30, 2015, when the spacecraft, which had run out of fuel, purposely crashed onto the planet's surface for scientists to observe the results.

In 2012, scientists discovered a group of meteorites in Morocco that they think could have originated from the planet Mercury. If so, it would make the rocky planet a member of a very select club with samples available on Earth; only the moon, Mars and the large asteroid Vesta have verified rocks in human laboratories.

In 2016, scientists released the first-ever global digital-elevation model of Mercury, which combined more than 10,000 images acquired by MESSENGER to take viewers across the wide-open spaces of the tiny world. The model revealed the planet's highest and lowest points - the highest is found just south of Mercury's equator, sitting 2.78 miles (4.48 km) above the average elevation of the planet, while the lowest point resides in Rachmaninoff basin, the suspected home of some of the most recent volcanic activity on the planet, and lies 3.34 miles (5.38 km) below the landscape average.

In 2018, a new Mercury explorer was launched. The BepiColombo mission jointly operated by the European and Japanese space agencies is composed of two spacecraft - Mercury Planetary Orbiter and the Mercury Magnetospheric Orbiter - that, after a long trek to Mercury, will split up to better understand the tiny world. The European Space Agency's segment of the mission will focus on studying Mercury's surface while the Japan Aerospace Exploration Agency's portion will focus on the planet's strange magnetosphere.

In 2021, BepiColumbo captured its first views of Mercury during a gravity assist flyby. BepiColumbo is scheduled to arrive at Mercury in late 2025, and gather data during its one-year nominal mission with the possibility of a one-year extension, according to ESA.

Mercury images

Mercury quiz

Additional resources

Learn more about Mercury at NASA's Solar System Exploration website. Read about MESSENGER's top science results via Johns Hopkins Applied Physics Laboratory. See MESSENGER's crater on Mercury, made when the spacecraft deliberately crashed into the planet

Bibliography

Strom, Robert G., and Ann L. Sprague. Exploring Mercury: the iron planet. New York: Springer, 2003.

Charlier, Bernard, and Olivier Namur. " The origin and differentiation of planet Mercury." Elements: An International Magazine of Mineralogy, Geochemistry, and Petrology 15.1 (2019): 9-14.

Mangano, Valeria, et al. " BepiColombo science investigations during cruise and flybys at the Earth, Venus and Mercury." Space Science Reviews 217.1 (2021): 1-81.

Hauck, Steven A., and Catherine L. Johnson. " Mercury: Inside the iron planet." Elements: An International Magazine of Mineralogy, Geochemistry, and Petrology 15.1 (2019): 21-26.

# data[].attributes.attachment_link.title
Planet Mercury: Facts About the Planet Closest to the Sun

# data[].attributes.attachment_link.description
Mercury is the closest planet to the sun and the smallest planet in the solar system. We explore Mercury along with its short years, long days and odd sunsets.

# data[].attributes.attachment_link.readable_text
Size of Venus compared to the Earth

Side by side comparison of the size of Venus vs Earth

Facts about Venus

Venus is the second brightest natural object in the sky. The planet has an apparent magnitude of -3.8 to -4.6, which makes it visible on a bright, clear day. The Moon is the only other natural object that is brighter.

Venus is sometimes referred to as the "morning star" and "evening star". This dates back to ancient civilizations who believed that Venus was in fact two distinct stars appearing in the sky. When the orbit of Venus overtakes Earth's orbit, it changes from being visible at sunrise to being visible at sunset. They were known as Phosphorus and Hesperus by the Greeks, and Lucifer and Vesper by the Romans.

One day on Venus is longer than one year. Due to the slow rotation on its axis, it takes 243 Earth-days to complete one rotation. The orbit of the planet takes 225 Earth-days - making a year on Venus shorter on day on Venus.

Venus is named after the Roman goddess of love and beauty. This may be, in part, due the brightness of the planet and may date back to the Babylonians in 1581 who referred to Venus as "bright queen of the sky".

Venus is sometimes called Earth's sister planet. This is because their size is very similar (there is only a 638 km different in diameter) and Venus has around 81% of Earth's mass. They are also similarly located with Venus being the closest planet to Earth. Both planets also have a central core, a molten mantle and a crust.

Venus has no moons nor rings.

Billions of years ago, the climate of Venus may been similar to that of Earth and scientists believe that Venus once possessed large amounts of water or oceans. However, due to the high temperatures produce from the extreme greenhouse effect, this water boiled off long ago and the surface of the planet is now too hot and hostile to sustain life.

Venus rotate in the opposite direction to other planets. Most other planets rotate counter-clockwise on their axis, however Venus, like Uranus, rotates clockwise. This is known as a retrograde rotation and may have been caused by a collision with an asteroid or other object which caused the planet to change its rotational path.

Venus is the hottest planet in the solar system with an average surface temperature of 462°C (863°F). Also, Venus doesn't tilt on its axis which means there are no seasons either. The atmosphere is a dense 96.5% carbon dioxide which traps heat and caused the greenhouse effect which evaporated any water sources billions of years ago.

The temperature on Venus doesn't vary much between the night and day. This is due to the slow movement of the solar winds across the surface of the planet.

The estimated age of the Venusian surface is around 300-400 million years old. By comparison, the surface of the Earth is about 100 million years old.

The atmospheric pressure of Venus is 92 times stronger than Earth's. This means that any small asteroids entering the atmosphere of Venus are crushed by the immense pressure, which is why there are no small surface craters on the planet. This pressure is equivalent to being around 1,000 km under Earth's oceans.

Venus has a very weak magnetic field. This surprised scientists, who expected Venus to have a magnetic field similar in strength to Earth's. One possible reason for this is that Venus has no solid inner core, or that its core is not cooling.

Venus is the only planet in the Solar System to be named after a female figure.

Venus orbits the sun in an ellipse, but its orbit is the closest to being a circle out of all the planets in the Solar System.

Venus is the closest planet to Earth. When Venus is in line with Earth and the Sun, it is the closest planet to us, at an average distance of 41 million kilometers (25.5 million miles) away.

More information and Facts about Venus

By the time of the ancient Romans it was understood that Venus was one of four planets other than the Earth. Being the brightest and most visible of these planets, the Romans named Venus after their goddess of love and beauty. As a result of its name, the planet has naturally been associated with love, femininity, and romance throughout history.

It is often remarked that Venus and Earth are twin planets due to their similarity in size, density, mass, and volume. Though these planetary characteristics are relatively the same, Venus and Earth are still substantially different in many other ways (atmosphere, rotation, surface temperatures, and Venus' lacking a moon). If the twin relationship remains, it should be noted that they are not identical.

As with Mercury, our knowledge of Venus has grown considerably during the latter half of the twentieth-century. For example, prior to the several planetary missions conducted by NASA and the Soviet Union beginning in the 1960s, scientists had been hopeful that conditions beneath the extremely dense clouds covering the planet would allow for life. Unfortunately, the data collected during these missions proved that the conditions present were too severe to support life.

Atmosphere

Venus' atmosphere can be divided into two broad layers. The first is the cloud bank that effectively encases the entire planet. The second is everything below these clouds.

The clouds surrounding Venus extend from 50 to 80 kilometers above the planet's surface and are composed primarily of sulphur dioxide (SO ₂) and sulphuric acid (H ₂SO ₄). These clouds are so dense that they reflect 60% of the sunlight Venus receives back into space.

The atmosphere of Venus gives it a light yellowish appearance.

When studying the sub-cloud atmosphere two features are immediately prominent: density and composition. Furthermore, the effect these two features produce on the planet is profound, making Venus the hottest and least hospitable of any planet in the Solar System.

Firstly, with an atmospheric density of approximately , the resulting atmospehric pressure is ninety-two times that found at sea level on Earth. The magnitude of this difference is substantial. To put it in perspective, one would have to travel to a depth of roughly one kilometer beneath the ocean surface to find the same pressure on Earth.

Secondly, the sub-cloud atmosphere's composition is roughly 97% carbon dioxide (CO ₂) with the remaining 3% being primarily Nitrogen (N ₂). Thus, there is an extremely thick zone of carbon monoxide between the high altitude cloud layer and the planet's surface. The outcome of this environment is a very intense manifestation of what is known as the greenhouse effect; that is, heating caused by the atmospheric trapping of solar radiation.

Greenhouse Effect

In the case of Venus, the greenhouse effect begins when small amounts of solar radiation in the form of visible light penetrate the dense cloud layer. Once this radiation is absorbed by the surface, it is converted into heat and emitted back into the atmosphere. At this point, however, the heat is unable to pass back through the carbon dioxide zone as easily as the light. (This is due to the intrinsic properties of the carbon dioxide.) Instead, the heat is absorbed by the carbon dioxide, then radiated in part back toward the planet's surface. The cumulative effect is a constant abundance of heat, which, in turn, causes the surface temperature to remain at a permanent and severe 480° C. This easily makes Venus' surface the hottest of any planet's in the solar system.

Surface

Due to the thick clouds enshrouding Venus, the details of its surface cannot be obtained through simple photographic means. Fortunately, scientists have been able to use the method of radar mapping to acquire this information instead. While both photography and radar imaging work by collecting radiation that has bounced off an object, the difference lies in the forms of radiation collected. Photography collects visible light radiation, and radar mapping collects microwave radiation. The advantage in using radar mapping with Venus is that microwave radiation is able to pass through the planet's thick clouds, whereas the light necessary for photography is unable to do so.

The first radar mappings of the Venusian surface via spacecraft came in 1978 when the Pioneer Venus spacecraft began orbiting the planet. What the resulting maps revealed was a surface consisting primarily of plains formed by ancient lava flows, with only two highland regions, Ishtar Terra and Aphrodite Terra.

In 1990, the Magellan spacecraft began orbiting Venus. In addition to performing radar mapping similar to that of Pioneer Venus, Magellan also undertook a more advanced radar imaging that gathered much finer details. What Magellan found was approximately 1000 impact craters. Interestingly, none of the craters seen were less than 2 km in diameter. This suggest that any meteroid small enough to create a crater having a diameter less than 2 km would have broken apart and burned up during its passage through the dense Venusian atmosphere.

Size Matters

An additional observation regarding the size of the impact craters helped to shed light on the age of the planet's surface. Not only were small impact craters absent on the planet's surface, but also those of large diameter. What this tells us is that the surface has been formed since the period of heavy bombardment, a span of 3.8 to 4.5 billion years ago when a large number of impact craters were formed on the inner planets. Thus, geologically speaking, the Veunsian surface is relatively young.

Finally, the surface's most prominent features are those produced by the planet's volcanic activity. As noted above, the first of these features is the enormous plains caused by ancient lava flows. Covering over 80% of the Venusian surface, these plains are the most dominant feature. The second prominent feature is the surface's volcanic structures, which are numerous and varied. In addition to shield volcanoes similar to those found on Earth (e.g., Mauna Loa), many "pancake" volcanoes have been observed on Venus. These volcanoes, unlike any on Earth, are believed to have formed their distinctive flat, disc-like shape due to an eruption of all of the volcano's lava at once through a single vent. After such an eruption, the lava then spreads outwardly in a uniform, circular manner.

Interior

As with the other terrestrial planets, Venus' interior is essentially composed of three layers: a crust, a mantle, and a core. However, what is intriguing about Venus' interior (as opposed to that of Mercury or Mars) is how alike it is to the Earth's interior. While it is impossible to test the true similarity of the two planets' interiors, it is reasonable to draw such conclusions based on the characteristics the two planets are known to share. Hence, it is believed that Venus' crust is 50 km thick, its mantle 3,000 km thick, and the core has a diameter of 6,000 km.

An unanswered question about the Venusian interior is whether or not the planet's core is liquid or solid. On one hand, because Venus and Earth are so alike, it is reasonable to conclude that since Earth has a liquid core, Venus does as well.

On the other hand, there is also evidence to suggest the Venusian core is solid. This evidence stems from the planet's lacking a substantial magnetic field. Simply put, planetary magnetic fields are a result of the transfer of heat from inside a planet to its surface. A necessary component of this transfer is a liquid core. The argument is since Venus lacks a substantial magnetic field, it cannot possess a liquid core.

Orbit & Rotation

The most notable aspect of Venus' orbit is its uniformity of distance from the Sun. Indeed, with an eccentricity of only .00678, Venus' orbit is easily the most circular of all the planets. Moreover, this small eccentricity means that the difference between Venus' perihelion () and its aphelion () is a mere .

Like information regarding Venus' surface, little data about its rotation could be obtained until the radar imaging missions of the second half of the twentieth-century. Surprisingly, what these missions revealed was just how unique Venus' rotation is.

Whereas the standard rotation for a planet about its axis is counterclockwise (as viewed from the "top" of the orbital plane), Venus' rotation is retrograde or clockwise. The reason for this is presently unknown, but there are two popular theories. The first points to the 3:2 spin-orbit resonance of Venus with the Earth.

Outside Interference

To some, this is highly suggestive that over billions of years the Earth's gravitational force has altered Venus' rotation to its present state. Some scientists, however, doubt that the Earth's gravitational force has been great enough to change Venus in such a fundamental way. Instead, they have looked to the early Solar System when the planets were being formed to provide an explanation. They theorize that Venus' original rotation was similar to that of the other planets', yet it was altered to its current orientation when a large planetesimal struck the young planet with great force, essentially knocking the planet upside down.

A second unexpected discovery regarding Venus' rotation is its speed. Taking approximately 243 Earth days to complete a single rotation, a day on Venus is longer than on any other planet. This alone is noteworthy. What is even more striking, though, is when Venus' day is compared to its year. At roughly 224 earth days, Venus' year is almost 19 earth days less than one Venusian day. Again, no other planet shares such a property. The leading theory for this phenomenon is that which is used to explain the planet's retrograde rotation.

Quick Venus Facts

# data[].attributes.attachment_link.title
Venus Facts: Interesting Facts about Planet Venus * The Planets

# data[].attributes.attachment_link.description
Venus is the second brightest natural object in the sky. The planet has an apparent magnitude of -3.8 to -4.6, which makes it visible on a bright, clear day. The Moon is the only other natural object that is brighter. Venus is sometimes referred to as the "morning star" and "evening star".

# data[].attributes.attachment_link.readable_text
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

# data[].attributes.attachment_link.title
Saturn Facts 🪐 - Interesting Facts about Planet Saturn

# data[].attributes.attachment_link.description
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,

# data[].attributes.attachment_link.readable_text
Jupiter is the fifth planet from our Sun and is, by far, the largest planet in the solar system - more than twice as massive as all the other planets combined.

Jupiter's stripes and swirls are actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium. Jupiter's iconic Great Red Spot is a giant storm bigger than Earth that has raged for hundreds of years.

Jupiter is named for the king of the ancient Roman gods.​

The biggest planet in our solar system has a large presence in pop culture, including many movies, TV shows, video games, and comics. Jupiter and its moons were notable destinations in "The Expanse" series, while various Jovian moons provide settings for "Cloud Atlas," "Futurama," "Power Rangers," and "Halo," among many others. In the movie "Men in Black" when Agent J - played by Will Smith - mentions he thought one of his childhood teachers was from Venus, Agent K - played by Tommy Lee Jones - replies that she is actually from one of Jupiter's moons.

# data[].attributes.attachment_link.description
Jupiter is the fifth planet from our Sun and is, by far, the largest planet in the solar system - more than twice as massive as all the other planets combined. Its iconic Great Red Spot is a giant storm bigger than Earth, and has raged for hundreds of years.

# data[].attributes.attachment_link.readable_text
Uranus is the seventh planet from the Sun, and has the third-largest diameter in our solar system. It was the first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel, although he originally thought it was either a comet or a star.

It was two years later that the object was universally accepted as a new planet, in part because of observations by astronomer Johann Elert Bode. Herschel tried unsuccessfully to name his discovery Georgium Sidus after King George III. Instead, the scientific community accepted Bode's suggestion to name it Uranus, the Greek god of the sky, as suggested by Bode.​

Go Farther

Everything you need to know about Uranus.

Uranus In Depth

Ten Things to Know About Uranus
Pop Culture

Uranus is the source of more than a few jokes and witty (and not so witty) puns, but the ice giant and its moons has been a serious destination various fictional stories, and on TV shows such as "Doctor Who." The radioactive element uranium was named after Uranus when it was discovered in 1789, just eight years after the planet was discovered.

Read More

# data[].attributes.attachment_link.description
The seventh planet from the sun with the third largest diameter in our solar system, Uranus is very cold and windy.

# data[].attributes.attachment_link.readable_text
Mars is the fourth planet from the Sun and is the second smallest planet in the solar system. Named after the Roman god of war, Mars is also often described as the "Red Planet" due to its reddish appearance. Mars is a terrestrial planet with a thin atmosphere composed primarily of carbon dioxide.

Facts about Mars

Mars and Earth have approximately the same landmass.
Even though Mars has only 15% of the Earth's volume and just over 10% of the Earth's mass, around two thirds of the Earth's surface is covered in water. Martian surface gravity is only 37% of the Earth's (meaning you could leap nearly three times higher on Mars).

Mars is home to the tallest mountain in the solar system.
Olympus Mons, a shield volcano, is 21km high and 600km in diameter. Despite having formed over billions of years, evidence from volcanic lava flows is so recent many scientists believe it could still be active.

Only 18 missions to Mars have been successful.
As of September 2014 there have been 40 missions to Mars, including orbiters, landers and rovers but not counting flybys. The most recent arrivals include the Mars Curiosity mission in 2012, the MAVEN mission, which arrived on September 22, 2014, followed by the Indian Space Research Organization's MOM Mangalyaan orbiter, which arrived on September 24, 2014. The next missions to arrive will be the European Space Agency's ExoMars mission, comprising an orbiter, lander, and a rover, followed by NASA's InSight robotic lander mission, slated for launch in March 2016 and a planned arrival in September, 2016.

Mars has the largest dust storms in the solar system.
They can last for months and cover the entire planet. The seasons are extreme because its elliptical (oval-shaped) orbital path around the Sun is more elongated than most other planets in the solar system.

On Mars the Sun appears about half the size as it does on Earth.
At the closest point to the Sun, the Martian southern hemisphere leans towards the Sun, causing a short, intensely hot summer, while the northern hemisphere endures a brief, cold winter: at its farthest point from the Sun, the Martian northern hemisphere leans towards the Sun, causing a long, mild summer, while the southern hemisphere endures a lengthy, cold winter.

Pieces of Mars have fallen to Earth.
Scientists have found tiny traces of Martian atmosphere within meteorites violently ejected from Mars, then orbiting the solar system amongst galactic debris for millions of years, before crash landing on Earth. This allowed scientists to begin studying Mars prior to launching space missions.

Mars takes its name from the Roman god of war.
The ancient Greeks called the planet Ares, after their god of war; the Romans then did likewise, associating the planet's blood-red colour with Mars, their own god of war. Interestingly, other ancient cultures also focused on colour - to China's astronomers it was 'the fire star', whilst Egyptian priests called on 'Her Desher', or 'the red one'. The red colour Mars is known for is due to the rock and dust covering its surface being rich in iron.

There are signs of liquid water on Mars.
For years Mars has been known to have water in the form of ice. The first signs of trickling water are dark stripes or stains on crater wall and cliffs seen in satellite images. Due to Mars' atmosphere this water would have to be salty to prevent it from freezing or vaporising.

One day Mars will have a ring.
In the next 20-40 million years Mars' largest moon Phobos will be torn apart by gravitational forces leading to the creation of a ring that could last up to 100 million years.

Sunsets on Mars are blue.
During the martian day the sky is pinkish-red, this is the opposite of the Earth's skies.

Mars Diagrams

Mars size compared to Earth

Mars distance from the Sun and orbital eccentricity

Mars Features

Moons

Mars has two small moons, Phobos and Deimos. They were discovered in 1877 by astronomer Asaph Hall, who named them for the Latin terms "fear" and "panic". These moons are thought to be captured asteroids and are among the smallest natural satellites in the solar system.

Olympus Mons

Mars has the largest volcano in the solar system - Olympus Mons. It measures some 600 kilometres across and rises nearly 27 kilometres above the surrounding terrain. It is a shield volcano built by the continuous action of flowing lava over millions and millions of years that began some 3 billion years ago.

Olympus Mons is part of a complex of volcanoes that lie along a volcanic plateau called the Tharsis Bulge. This entire region lies over a hotspot, a place in the planet's crust that allows magma from deep inside to flow out to the surface.

Valles Marineris

The Valles Marineris is an extensive canyon system on the Mars equator. It is 4,200 kilometres long and, in places, is 7 kilometres deep. On Earth, it would span the entire North American continent and beyond.

Mars has has a very primitive form of plate tectonics, and the action of two plates past each other began splitting the surface some 3.5 billion years ago. That set the stage for the formation of the Valles Marineris.

Sources: https://solarsystem.nasa.gov/planets/mars/overview/ , https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html, https://astrogeology.usgs.gov/maps/mars-viking-hemisphere-point-perspectives
First Published: June 2012
Last Updated: May 2020
Author: Chris Jones

# data[].attributes.attachment_link.title
Mars Facts - Interesting Facts about Planet Mars

# data[].attributes.attachment_link.description
Mars is the fourth planet from the Sun and is the second smallest planet in the solar system. Named after the Roman god of war, Mars is also often described as the "Red Planet" due to its reddish appearance. Mars is a terrestrial planet with a thin atmosphere composed primarily of carbon dioxide.

# data[].attributes.attachment_link.readable_text
Neptune is the eighth planet from the Sun, making it the most distant in the solar system. This gas giant may have formed much closer to the Sun in the early solar system history before migrating out to its current position.

Facts about Neptune

Neptune is the most distant planet from the Sun.

Neptune is the smallest gas giant.

A year on Neptune lasts 165 Earth years.

Neptune is named after the Roman god of the sea.

Neptune has 6 faint rings.

Neptune was not known to the ancients.
It is not visible to the naked eye and was first observed in 1846. Its position was determined using mathematical predictions. It was named after the Roman god of the sea.

Neptune spins on its axis very rapidly.
Its equatorial clouds take 16 hours to make one rotation. This is because Neptune is not solid body.

Neptune is the smallest of the ice giants.
Despite being smaller than Uranus, Neptune has a greater mass. Below its heavy atmosphere, Uranus is made of layers of hydrogen, helium, and methane gases. They enclose a layer of water, ammonia and methane ice. The inner core of the planet is made of rock.

The atmosphere of Neptune is made of hydrogen and helium, with some methane.
The methane absorbs red light, which makes the planet appear a lovely blue. High, thin clouds drift in the upper atmosphere.

Neptune has a very active climate.
Large storms whirl through its upper atmosphere, and high-speed winds track around the planet at up 600 meters per second. One of the largest storms ever seen was recorded in 1989. It was called the Great Dark Spot. It lasted about five years.

Neptune has a very thin collection of rings.
They are likely made up of ice particles mixed with dust grains and possibly coated with a carbon-based substance.

Neptune has 14 moons.
The most interesting moon is Triton, a frozen world that is spewing nitrogen ice and dust particles out from below its surface. It was likely captured by the gravitational pull of Neptune. It is probably the coldest world in the solar system.

Only one spacecraft has flown by Neptune.
In 1989, the Voyager 2 spacecraft swept past the planet. It returned the first close-up images of the Neptune system. The NASA/ESA Hubble Space Telescope has also studied this planet, as have a number of ground-based telescopes.

Neptune Diagrams

Neptune size compared to Earth

Neptune distance from the Sun and orbital eccentricity

Neptune's Great Dark Spot

The Great Dark Spot in the southern atmosphere of Neptune was first discovered in 1989 by the Voyager 2 spacecraft. It was an incredibly large rotating storm system with winds of up to 1,500 miles per hour, the strongest winds recorded on any planet. How such powerful winds were discovered on a planet so far from the sun is still considered a mystery to this day.

Data from the Voyager 2 spacecraft also showed that the Great Dark Spot varied significantly in size during their brief pass of the planet. When Neptune was viewed by the Hubble Space telescope in 1994 the Great Dark Spot had vanished, although a different dark spot had appeared in Neptune's northern hemisphere.

Neptune's Atmosphere

Neptune has an incredibly thick atmosphere comprised of 74% hydrogen, 25% helium and approximately 1% methane. Its atmosphere also contains icy clouds and the fastest winds recorded in the solar system. Particles of icy methane and minor gases in the extremities of the atmosphere give Neptune its deep blue colour. The striking blue and white features of Neptune also help to distinguish it from Uranus.

Neptune's atmosphere is subdivided into the lower troposphere and the stratosphere with the tropopause being the boundary between the two. In the lower troposphere temperatures decrease with altitude however they increase with altitude in the stratosphere. Hydrocarbons form hazes of smog that appear in the entire upper atmosphere of Neptune and hydrocarbon snowflakes that form in Neptune's atmosphere melt before they reach its surface due to the high pressure.

# data[].attributes.attachment_link.title
Neptune Facts - Interesting Facts about Planet Neptune

# data[].attributes.attachment_link.description
Neptune is the eighth planet from the Sun, making it the most distant in the solar system. This gas giant may have formed much closer to the Sun in the early solar system history before migrating out to its current position. Neptune is the most distant planet from the Sun.

# data[].attributes.attachment_link.provider_name
Farmers' Almanac - Plan Your Day. Grow Your Life.

# data[].attributes.attachment_link.readable_text
You may have heard people complaining about something called Mercury retrograde. But what is it? And when are the dates? We have the answers!

April 1- 25, 2024

August 5- 28, 2024

November 25, 2024-December 15, 2024

What does "Mercury Retrograde" mean?

The term retrograde comes from the Latin word retrogradus, which literally means "backward step." As the name suggests, retrograde is when a planet appears to go backward in its orbit, as viewed from Earth. Astronomers refer to this as "apparent retrograde motion," because it is an optical illusion.

The opposite of retrograde is direct or prograde motion. Prograde motion is the term astronomers prefer, while astrologers are more prone to use the term "direct" motion.

Apparent Backward Motion

Every planet in our Solar System travels in the same direction in its journey around the Sun, and none of them ever pause and turn back in the opposite direction. Yet, all of them appear to do just that from time to time.

Because of the Earth's daily rotation, the objects in the night sky appear to "move" from east to west in the night sky. While the location of the stars relative to the Earth is fixed, at least from our vantage point, the other planets in our Solar System all orbit the Sun at varying speeds.

The outer planets-Mars, Jupiter, Saturn, Uranus, and Neptune-take longer to orbit the Sun than the Earth does, because their orbits are larger. For this reason, the Earth often laps these planets in its journey around the Sun.

When the Earth overtakes an outer planet, that planet appears to travel backward, as compared to the stars, for a time.

Picture two cars on the highway going in the same direction in different lanes. If one car is driving faster than the other, the slower car will appear to go backward from the perspective of a person in the faster car, even though the slower car is still going pretty fast in the same direction.

For the inner planets, Mercury and Venus, the mechanism that causes them to turn retrograde is the same, but in reverse. Mercury and Venus appear to go retrograde when they lap us.

Because Mercury completes its orbit around the Sun in only 88 days, the Swift Planet becomes retrograde three or four times in a calendar year, for about three weeks at a time. Outer planets have less frequent, but longer-lasting, periods of retrograde motion.

Why Dread It?

So what does all of that have to do with people wanting to hide in their rooms for weeks at a time?

Astrologers believe that the Moon, stars, planets, and Sun affect happenings here on Earth and that each planet in our Solar System rules a different aspect of life. Learn more about this.

Like the Greek messenger god it was named for, Mercury is said to govern transportation and communication.

Those who dread Mercury's retrograde motion say that, when the planet travels backward, its power to positively influence these domains is stifled, leading to chaos.

Believers in the malevolent power of Mercury retrograde blame the phenomenon for everything from arguments to lost mail or luggage to automobile accidents and technology issues, and warn people to hold back on conducting important business during this time.

The Bright Side

Mercury retrograde gets a bad wrap, but some believe it is possible to use these time frames to learn more about yourself, your community, and others. According to astrology, each Mercury retrograde involves Mercury traveling backward through a different zodiac sign. Learn more about this.

Related Articles
Other Planets Retrograde And Symbolism More fascinating facts about Mercury
Join the Discussion!

Do you believe that Mercury retrograde causes disasters?

What is the wildest thing that happened to you during Mercury retrograde?

Let us know in the comments below!

# data[].attributes.attachment_link.title
Mercury Retrograde 2024: What Is It And Dates

# data[].attributes.attachment_link.description
You've heard the term Mercury retrograde, but do you know what it means? Those who believe in astrology believe ...

# data[].attributes.attachment_link.readable_text
First, identify which zodiac sign Venus occupies. This is a critical first step, as the planet's sign will reveal precisely how it wants to indulge. Venus in Cancer, for instance, seeks security in partnership, while Venus in Aquarius is fueled by more unorthodox dynamics. Once you've identified Venus's sign, take a look to see what connections (in astrospeak, "aspects") it's making with the other planets in your birth chart.

If Venus is linked to Mercury, for example, communication will play a significant role within your relationships. If Venus is working closely with Saturn, however, Venus's hedonistic sensibilities may be tempered by Saturn's signature stoicism. Venus's connection to Mars, accordingly, reveals the interplay of sex and love: Do they work harmoniously, or serve entirely different purposes?

Venus is an essential piece in your personal cosmic puzzle. This benevolent planet reminds us that, at the end of the day, we deserve love.

Venus's attitude is also influenced by which astrological house it occupies. The birth chart is divided into 12 segments, referred to as "houses," each representing a different area of life. For instance, someone with a Leo Venus in the sixth house (which represents your daily routines) may always be seeking opportunities to perform and attract attention within their office environment. Alternatively, an individual who has Gemini Venus in their second house, which symbolizes personal finances, may achieve monetary success by pursuing multiple careers or side hustles simultaneously.

Your birth chart is a fully functioning ecosystem. It comes pre-assembled; there are no missing parts or broken pieces. The planets tell a story, and as you continue to study their positions - their signs, locations, and relationships with the other celestial bodies - you begin to unlock your unique cosmic narrative. Your chart exists for a reason, but it's up to you to interpret your individual truth. Venus is an essential piece in your personal cosmic puzzle. This benevolent planet reminds us that, at the end of the day, we deserve love.

Venus Through The Signs

Venus's mission is to give and get pleasure, or what the planet perceives as pleasure is dictated by its zodiac sign. Once you discover which sign Venus occupies for you (do this by calculating your natal chart), use these descriptions of Venus sign meanings as a jumping-off point for further exploration.

Aries are strong and mighty warriors. Even Venus - the most sensual planet in the sky - is no match for the fiery energy of an Aries. When Venus occupies Aries, it thrives on competition: They simply love the chase. People with Aries Venus adore flirtatious romances that are defined by physical touch, exciting spontaneity, and (of course) some playful bickering to keep the flame burning.

Taurus is governed by Venus, so these combined energies blend harmoniously. As an earth sign, Taurus loves to indulge its five sense through luxurious fabrics, enchanting aromas, and gentle caresses. Although Taurus Venus's are extremely romantic, they also know how to advocate for what they want. Taurus Venus needs a relationship that's rooted in reality - if this sign feels unsupported, they will seek comfort elsewhere.

As an air sign, Gemini is all about communication. Likewise, a Gemini Venus is drawn to information like a moth to a flame. Expression is critical for the Gemini Venus soul, so those born under this chatty sky find pleasure when pursuing their curiosities. Moreover, since Gemini also is linked to local community, for Venus Gemini, there is often no distinction between friend and lover - in fact, Gemini Venus prefers the ambiguity. Hey, it's more fun that way.

Cancer, symbolized by the crab, protects its soft interior with a tough exterior. In order for these celestial crustaceans to open up, they need to feel safe and secure. Accordingly, nothing is more rewarding to a Cancer Venus than building a relationship based on trust, loyalty, and protection. Just as the crab carries its domicile on its back, Cancer Venus is happiest when building a partnership that feels like home.

Leo governs the heart, and fittingly, those born under the Leo Venus sky are true romantics. Regal and generous, Leo Venus loves to worship (and be worshiped by) their partners. This fiery Venus idealizes the concept of a "power couple" - after all, Venus Leo is constantly seeking its co-ruler. For Leo Venus, a partnership is personal, because they see it as a reflection of their own identity. So, when this sign feels rejected, proceed with caution, as lions can also be extremely ferocious.

Virgo Venus people love to problem-solve, and fittingly, seek a partnership that is based on reciprocity. Virgo's earthy energy is practical and organized, so when fused with sensual Venus, this placement is wooed by thoughtful acts of service. Small and subtle gestures make Virgo Venus's heart aflutter. For these sweet lovers, there is truly nothing more romantic than when their closest companion lends a helping hand.

In addition to Taurus, Venus also governs Libra, so Venus is extremely comfortable working with Libra energy. However, while Taurus Venus is all about physical sensuality, Libra Venus is much more cerebral. Symbolized by the scales, Libra is obsessed with balance, harmony, and symmetry. Fittingly, Libra Venus people are total aesthetes. Those born with this placement love indulging their exquisite style and taste within their partnerships. Simply put, Libra Venus needs to be in a relationship that looks good.

Scorpions are shadow dwellers, and similarly, celestial Scorpios derive their dynamic power from the unseen realms. When sensual Venus occupies this sign, it is enchanted by intense, mysterious, and karmic bonds. Scorpio Venus loves anything with a dash of danger, so those born under this elusive sky crave deep, erotic intimacy that illuminates from the inside.

Sagittarius is associated with travel, discovery, and philosophy. Fittingly, when the planet of love occupies this sign, Venus's gaze shifts from romance to rodeos. People with Sagittarius Venus are drawn to explorers, nomads, and daredevils. Adventure is a huge turn-on for these fiery lovers, but nothing excites Sagittarius Venus more than a good sense of humor. Sagittarius Venus love to be entertained, so laughter will always be their number one aphrodisiac.

Capricorn is the boss of the zodiac, and those with Capricorn Venus are always seeking their proverbial daddy. Although Venusian energy is tempered by Capricorn's signature stoicism, this planet finds its erotic outlet by experimenting with power dynamics and role play. Because Capricorn abides by the "all work and no play" mantra, people born under the Capricorn Venus get off on pushing these limits.

Aquarius energy is progressive, offbeat, and aloof. Accordingly, those who have Aquarius Venus find pleasure in nonconformity. In fact, for the Aquarius Venus lover, the ideal partnership cannot be defined, because Aquarius Venus refuses to describe their interpersonal bonds through societal conventions. Naturally, Aquarius Venus also gravitates towards eccentric, free-spirited, and rebellious individuals. When it comes to love, this Venusian placement lets its freak flag fly.

The last sign of the zodiac, the Pisces spirit is mystical and ethereal. Although Pisces energy can be hard to contain (after all, the ocean is boundless), Venus absolutely adores dwelling in this sign. In fact, Venus is considered "exalted" in Pisces, meaning that in this sign, Venus is functioning at its highest vibration. Pisces Venus finds beauty in absolutely everything and is particularly drawn to creative pursuits such as music and art. For these lovers, romance is deeply spiritual.
More on astrology: Now, watch Liza Koshy try nine things she's never done before: Find Aliza on Instagram, Twitter, and her website.

# data[].attributes.attachment_link.title
What the Position of Venus in Your Birth Chart Means for You

# data[].attributes.attachment_link.description
First, identify which zodiac sign Venus occupies. This is a critical first step, as the planet's sign will reveal precisely how it wants to indulge. Venus in Cancer, for instance, seeks security in partnership, while Venus in Aquarius is fueled by more unorthodox dynamics.

# data[].attributes.attachment_link.readable_text
Saturn is the sixth planet from the Sun and the second largest planet in our solar system. Adorned with a dazzling system of icy rings, Saturn is unique among the planets.

It is not the only planet to have rings, but none are as spectacular or as complex as Saturn's. Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and helium.

The farthest planet from Earth discovered by the unaided human eye, Saturn has been known since ancient times. The planet is named for the Roman god of agriculture and wealth, who was also the father of Jupiter.

Perhaps the most iconic of all the planets in our solar system, Saturn is heavily present in pop culture.

It provides a backdrop for numerous science fiction stories, movies, and TV shows, comics, and video games, including the "Cthulhu Mythos," "WALL-E," "2001: A Space Odyssey," and "Star Trek." In Tim Burton's film "Beetlejuice," a dusty, fictional Saturn is populated by giant sandworms. And in the 2014 movie "Interstellar," the wormhole that enables the astronauts to travel to another galaxy appears near Saturn.

Saturn is also the namesake of Saturday, arguably the best day of the week.​

Discover More Topics From NASA

# data[].attributes.attachment_link.description
Planet Saturn Overview Saturn is the sixth planet from the Sun and the second largest planet in our solar system. Adorned with a dazzling system of icy rings, Saturn is unique among the planets. It is not the only planet to have rings, but none are as spectacular or as complex as Saturn's.

# data[].attributes.attachment_link.readable_text
Jupiter is named after the Roman king of the gods for good reason. It's the largest planet in the solar system and has more moons than any other planet. But that's not all. Read on for more facts about one of the most amazing planets in the solar system.

1. Jupiter is the king of planets by mass

Credit: Pixabay.

Everyone's learned at school that Jupiter is the largest planet in the solar system. However, this is a bit of an understatement. Jupiter is by far the most massive cosmic body in the solar system, being 2.5 times more massive than all other planets combined. It is nearly 318 times more massive than Earth and it would take 11 Earths lined up next to each to match Jupiter's diameter.

2. Its Great Red Spot is actually a planetary-sized storm that has been raging on for centuries

Image of Jupiter's Great Red Spot processed using low resolution (wide angle) orange, green, and blue filtered images overlaying high resolution (narrow angle) orange images taken by Voyager 2 on July 8 1979. Credit: NASA/JPL-Caltech/Kevin M. Gill.

In 1665, famed Italian astronomer Giovanni Cassini observed a huge blemish south of Jupiter's equator. This 'Great Red Spot', as it's still called today, has been the subject of contention among astronomers for centuries. Some have proposed that the feature, which is large enough to contain 2-3 planets the size of Earth's diameter, is a huge storm. This is indeed the case, NASA scientists found after the Voyager 1 mission completed a flyby of the planet in 1979.

Scientists confirmed that the Great Red Spot is an extremely persistent anticyclonic storm, fueled by Jupiter's turbulent and fast-moving atmosphere.

The red spot spins anticlockwise and takes six Earth days to rotate completely. However, it remains a mystery why this stormy region is red. One possible explanation is the presence of red organic compounds.

The Great Red Spot might disappear in the next few centuries, though. During Cassini's observations, the size of the spot is estimated to have been 40,000 km, whereas today it is about half as large. However, astronomers are fairly confident a new giant red spot will appear somewhere else on Jupiter's surface, due to the planet's atmospheric dynamics.

3. The first astronomers to track Jupiter were Babylonians

It's no secret that the ancient Babylonians were skilled mathematicians. For instance, they understood the Pythagorean theorem nearly 4,000 years ago, or more than a millennium before Pythagoras himself was born.

Their mathematical prowess naturally extended to astronomy, regularly employing arithmetic to catalog the movements of celestial bodies and improve their astronomical predictions.

Mathieu Ossendrijver of Germany's Humboldt University of Berlin spent no less than 13 years studying 2,400-year-old tablets that contained what he described as a "small bunch of four weird trapezoid computations." He later found that the trapezoids encoded aspects of Jupiter's motion, including its appearances on the horizon.

4. Jupiter has the shortest day of all planets, despite its hefty size

For all its monstrous size and mass, you'd think Jupiter would be slow to rotate around its axis. However, it's the fastest spinning planet in the solar system, with a rotational velocity of 45,300 km/h.

As such, a day on Jupiter only lasts 9 hours and 55 minutes. A year, however, is much longer - Jupiter orbits the sun every 11.8 Earth years.

What's more, due to this rapid rotation, the planet has an oblate shape with flattened poles and a bulging equator. Its powerful rotation is also responsible for the next point.

5. Jupiter has the strongest magnetic field of any planet in the solar system

Schematic of the Jovian magnetosphere showing the Io Plasma Torus (in red), the Neutral Sodium immediately surrounding Io (in yellow), the Io flux tube (in green), and magnetic field lines (in blue). Credit: Wikimedia Commons, John Spencer.

Like Earth, Jupiter's core is made of active, swirling molten material whose motion generates a magnetic field - and a very powerful one to boot. According to measurements performed by NASA, Jupiter's magnetic field is at least 14 times stronger than Earth's, making it the most powerful in the solar system.

6. Jupiter has a thin ring system

A schematic of Jupiter's ring system. Credit: Wikimedia Commons.

This wouldn't be a list of facts about Jupiter without mentioning its rings. Unlike Saturn's more iconic rings, Jupiter's are very faint and made of dust rather than ice.

For centuries, these rings were too faint for astronomers to notice. Imagine everyone's surprise when NASA's Voyager 1 spacecraft beamed back images of Jupiter's rings in 1979. The three-ring system begins some 92,000 kilometers above Jupiter's cloud tops and stretches out to more than 225,000 km from the planet. They are between 2,000 to 12,500 kilometers thick.

7. Jupiter has 79 moons and counting

Jupiter's moon Ganymede in the foreground. Credit: Pixy.

Until recently, Jupiter was widely regarded as the planet of the solar system with the most natural satellites. That's until 2019, when astronomers affiliated with the Carnegie Institution for Science in Washington DC raised the total number of moons around Saturn to 82, beating Jupiter's 79.

Almost all of Jupiter's moons are tiny, with a diameter of less than 10 kilometers. This is also one of the reasons why astronomers are constantly finding new moons around both Jupiter and Saturn.

Jupiter does have some moons that stand out more. These four major moons are collectively known as Galilean Moons. They are Io, Europa, Ganymede, and Callisto. Ganymede, with a diameter of 5,262 km, is actually the largest moon in the solar system. And, who knows, perhaps Jupiter might regain its title as the most moon-populated planet as scientists believe it may have as many as 200 natural satellites orbiting it.

8. And some of these moons may actually be capable of harboring life

The Voyager and Galileo missions that sent spacecraft to Jupiter and its moons found that Europa, one of the biggest moons in the solar system, has a subsurface liquid ocean covered in thick ice. Now, scientists believe that Europa may actually be capable of harboring life since it meets three essential conditions: biochemically useful molecules, a source of energy, and a liquid solvent (water) in which dissolved substances can chemically react with each other.

But to ultimately find life on Europa, we have to get beneath the ice by one day putting a lander on the surface, potentially carrying a submarine.

9. Jupiter has the brightest auroras in the solar system

Artistic impression of an aurora on Jupiter.

From time to time, people are treated to nature's dazzling fireworks show; the Aurora borealis, also known as the Northern Lights. This eye candy phenomenon is caused by the collision of energetic charged particles with atoms in the high altitude atmosphere - and it's not reserved to Earth. Auroras have also been spotted on Mars, Uranus, and, yes, Jupiter.

Jupiter actually experiences the most intense auroras in the solar system, being hundreds of times brighter than on Earth. Just like on Earth, auroras on Jupiter are caused by solar storms. However, Jupiter has an additional source for its auroras: charged particles thrown into space by its orbiting moon Io, which is famous for its many large volcanoes.

10. Jupiter is a 'failed star'

The gas giant is virtually made of 90% hydrogen and 10% helium, that's mighty close to the sun's composition. In fact, some consider Jupiter to be a 'failed star'. Jupiter is already a big boy, but if it were roughly 80 times more massive than it is, it could have collapsed under its own gravity to form a star.

11. Jupiter is the solar system's asteroid vacuum cleaner

Due to its sheer mass and proximity to the Kuiper belt - a huge region of space beyond Neptune packed with asteroids and dwarf planets - Jupiter attracts a lot of visitors. Astronomers believe Jupiter experiences at least 200 times more meteorite impacts than Earth. So, kudos to Jupiter for clearing the solar system of potentially hazardous asteroids that might have come dangerously close to Earth.
Did we miss something? Share your favorite Jovian factoids in the comment section.

# data[].attributes.attachment_link.description
Jupiter is named after the Roman king of the gods for good reason. It's the largest planet in the solar system and has more moons than any other planet. But that's not all. Read on for more facts about one of the most amazing planets in the solar system.

# data[].attributes.attachment_link.readable_text
Size of Uranus compared with the Earth

Facts about Uranus

William Herschel discovered Uranus in 1781. The planet is too dim to have been seen by ancient civilizations. Herschel himself believed that Uranus was a comet at first, but several years later it was confirmed as a planet - making Uranus the first planet discovered in modern history. The original name proposed by Herschel was "Georgian Sidus" after King George III but the scientific community didn't take to it. Instead, Uranus was proposed and accepted by astronomer Johann Bode and it comes from ancient Greek god Ouranos.

Uranus rotates on its axis once every 17 hours and 14 minutes. Like Venus, it turns in a retrograde direction which is opposite to the direction Earth and the other six planets turn.

It takes Uranus 84 Earth days to orbit the Sun. Its axis is at 98 degrees, which means it almost lies sideways as it orbits the Sun. This means that the north and south poles of Uranus lie near where the equator is on Earth. During parts of its orbit one or other of the poles directly face the Sun which means the planet gets around 42 years of direct sunlight followed by 42 years of darkness.

A collision may have caused the unusual tilt of Uranus. The theory is that an Earth-sized planet may have collided with Uranus which forced its axis to drastically shift.

Uranus wind speeds can reach up to 900 km per hour. This is roughly 560 miles per hour.

The mass of Uranus is about 14.5 times the mass of Earth, making it the lightest of the four gas giants of the outer solar system.

Uranus is often referred to as the "ice giant". While it has a hydrogen and helium upper layer like the other gas giants, Uranus also has an icy mantle which surrounds its rock and iron core. The upper atmosphere of water, ammonia and methane ice crystals gives Uranus its distinctive pale blue color.

Uranus is the second least dense planet in the solar system, after Saturn.

The Voyager 2 is the only spacecraft to have flown by Uranus. This happened in 1986 and it flew past the planet at a distance of around 81,500 km. This mission returned the very first close-up images of the planet, its ring system and its orbiting moons.

Uranus has 13 presently known rings. All except two Uranian are extremely narrow - they are usually a few kilometres wide. It is believed that the rings are probably quite young. The matter within the rings is thought to be parts of a moon or moons that were shattered by high speed impacts with an object such as a comet or asteroid

The chemical element Uranium, discovered in 1789, was named after the newly discovered planet Uranus.

Uranus is the coldest planet in the solar system. The minimum surface temperature on Uranus is -224°C - making it the coldest of the eight planets. Its upper atmosphere is covered with a haze made mostly of methane which hides the storms taking place in its cloud decks.

The Uranian moons are named for characters created by Alexander Pope and William Shakespeare. For example, Oberan, Titania and Miranda. All these worlds are frozen with dark surfaces and some are a mixture of ice and rock. Of the Uranian moons, the most interesting is Miranda which has ice canyons, terraces and many strange looking surface area.

More information and facts about Uranus

Uranus has the distinction of being the first planet discovered in modern history. Actually, its discovery as a planet almost did not happen. In 1781, the astronomer William Herschel was charting the stars found in the Gemini constellation when he observed a disk-like object. His initial conclusion was that he had discovered a comet and reported his findings as such to the Royal Society of England. However, Herschel was puzzled when he calculated the object's orbit. Instead of the more elliptical path occurring with comets, he found that it was much more circular. This observation, which was confirmed by other astronomers at the time, led Herschel to conclude that he had, in fact, discovered a new planet. Shortly thereafter, it was widely accepted that Herschel had discovered an unknown planet.

As a result of his discovery, Herschel was given the privilege of naming the new planet. The name he chose was Georgium Sidus, which is latin for Georgian Planet. He opted for this name to honor then king of England, George III. This name, however, was not widely accepted, and as a result others began to suggest names. The name Uranus was put forth in the tradition of naming planets after deities in Roman mythology. Over time the scientific community accepted this as the planet's name.

At present, the only planetary mission to visit Uranus is Voyager 2. This lone encounter, which occurred in 1986, provided a large amount of data and discoveries. The spacecraft took thousands of pictures of Uranus and its moons and rings. Although the images of the planet showed little other than the uniform blue-green color seen from Earth-based telescopes, other images revealed the presence of ten previously unknown moons and two new rings. At this time, no future missions are scheduled for Uranus.

Atmosphere

Due to its stark blue appearance, the Uranian atmospheric patterns have been much more difficult to observe than, say, those of Jupiter or even Saturn. Fortunately, the Hubble Space Telescope has provided much more insight into the structural nature of Uranus' atmosphere. Through more advanced imaging technologies than Earth-based telescopes or Voyager 2, Hubble has shown that there are latitudinal bands much like those found on the other gas giants. Additionally, the winds associated with these bands can blow in excess of 576 km/hr.

The reason behind the monotonous atmospheric appearance is the composition of the top-most layer of the atmosphere. The visible cloud layers are composed primarily of methane, which absorbs those visible wavelengths corresponding to the color red. Thus, the reflected wavelengths are those of blue and green.

Beneath this outer methane layer, the atmosphere is composed of roughly 83% hydrogen (H ₂) and 15% helium with trace amounts of methane and acetylene. This composition is similar to that of the other gas giants. Uranus' atmosphere is drastically different in another regard, though. Whereas Jupiter and Saturn's atmospheres are primarily gaseous, Uranus' contains much more ice. This indicates that the Uranian atmosphere is extremely cold. In fact, at approximately -224° C, its atmosphere is the coldest found in the Solar System. What is even more interesting is data indicates that this extreme temperature is constant globally, occurring even on the side that is not sunlit.

Interior

Uranus' interior is thought to consist of two layers: a core and mantle. Current models suggest that the core is primarily composed of rock and ice and is approximately .55 times the mass of the Earth. The planet's mantle is believed to be 8.01 x 10 ²⁴ kg, or about 13.4 times the mass of the Earth. Furthermore, the mantle is composed of water, ammonia and other volatile elements. What distinguishes Uranus' mantle from those of Jupiter and Saturn is that it is icy, though not in the traditional sense. Instead, the ice is very hot and thick. The mantle is 5,111 km thick.

What is most surprising about Uranus' interior and one of the most distinguishing features with respect to the other gas giants is that it does not emit more energy than it receives from the Sun. Considering that even Neptune, which is very similar in size to Uranus, produces approximately 2.6 times the amount of heat that it receives from the Sun, scientists are very intrigued by the low heat that Uranus generates. There are two popular theories for this phenomenon. The first says that Uranus was struck by a large body, dispersing into space most of the heat that planets normally retain from their formations. The second theory claims that there is some barrier preventing the internal heat from making its way to the planet's surface.

Orbit & Rotation

When Uranus was discovered it expanded the radius of the known Solar System by almost a factor of two. What this means is that, on average, Uranus' orbit is about . The consequence of such an enormous distance is that it takes sunlight around two hours and forty minutes to reach Uranus&#8212that is almost twenty times as long as it takes sunlight to reach the Earth! This huge distance also means that a year on Uranus lasts almost 84 Earth years!

At 0.0473, Uranus' orbital eccentricity is just slightly less than that of Jupiter's .0484, making it the fourth most circular orbit of all the planets. The result of Uranus' fairly small orbital eccentricity is that the difference between its perihelion of and aphelion of is just .

Perhaps the most interesting thing about Uranus is how odd its rotation is compared to all of the other planets'. The axis of rotation for every planet other than Uranus is roughly perpendicular with their orbital plane. However, Uranus' axis is tilted almost 98°, which effectively means that Uranus rotates on its side. The result of this is that Uranus' north pole points at the Sun for half of its year, while the south pole points at the Sun the other half of its year! In other words, it is daytime on one Uranian hemispheres, while it is night time on the other for 42 Earth years at a time. Furthermore, due to this extreme rotation, Uranus does not have days like on other planets&#8212that is, the Sun doesn't rise and set like on other planets.

The cause for this highly unusual axial tilt is theorized to be the effect of a large body striking Uranus with such force that it essentially knocked the planet over on its side.

Rings

Although Saturn's rings have been well known for some time, it wasn't until 1977 that the planetary rings surrounding Uranus were discovered. The reason behind this is twofold: their distance from the Earth and their low reflectivity of light. Nonetheless, the Voyager 2 spacecraft identified two more on its fly-by mission in 1986, followed by the Hubble Space Telescope discovery of two additional rings in 2005. The total number of known rings currently sits at thirteen, the largest and brightest of which is the epsilon ring.

Uranus' rings differ from those found around Saturn in both the size of its particles and the particles' composition. First, the particles making up Saturn's rings are small, with few larger than several meters in diameter, whereas Uranus' rings contain many bodies up to twenty meters in diameter. Second, the particles of Saturn's rings are largely composed of ice. Uranus', however, are composed of both ice and considerable dust and debris.

# data[].attributes.attachment_link.title
Uranus Facts: Interesting Facts about Planet Uranus * The Planets

# data[].attributes.attachment_link.description
Size of Uranus compared with the Earth Facts about Uranus William Herschel discovered Uranus in 1781. The planet is too dim to have been seen by ancient civilizations. Herschel himself believed that Uranus was a comet at first, but several years later it was confirmed as a planet - making Uranus the first planet discovered ...

# data[].attributes.attachment_link.readable_text
If you were to look up in the eastern sky at the same time each night and note where Mars appears to be compared to the constellations of stars, you would find the planet a little farther east with each viewing. That is, Mars appears to move from west to east from one night to the next.

Every two years or so, there are a couple of months when Mars' position from night to night seems to change direction and move east to west. This strange behavior was very puzzling to early skywatchers. Did the planet really stop, back up, change its mind, and then continue to move forward? Did it have some weird, mystical meaning?

Today we know what's going on. It's an illusion, caused by the ways that Earth and Mars orbit the sun.

Mars Retrograde Happens Every Two Years

The two planets are like race cars on an oval track. Earth has the inside lane and moves faster than Mars -- so much faster, in fact, that it makes two laps around the course in about as much time as it takes Mars to go around once.

About every 26 months, Earth comes up from behind and overtakes Mars. While we're passing by the red planet this year, it will look to us as though Mars is moving up and down. Then, as we move farther along our curved orbit and see the planet from a different angle, the illusion will disappear and we will once again see Mars move in a straight line.

This apparent erratic movement is called "retrograde motion." The illusion also happens with Jupiter and the other planets that orbit farther from the sun.

Just to make things a little more odd, the orbits that Earth and Mars follow don't quite lie in the same plane. It's as if the two planets were on separate tracks that are a little tilted with respect to each other. This causes another strange illusion.

Suppose you were to draw a dot on a sky map each night to show where Mars appears as it moves forward, goes through retrograde, and then resumes its forward motion. Connect the dots, and you'll draw either a loop or an open zigzag. The pattern depends on where Earth and Mars happen to be in their tilted racetrack orbits.

These images show the apparent pattern made by the planet Mars while in 'retrograde motion' during 2014(left) and 2016(right) over Pasadena. The middle of the yellow line bends in a loop, giving the illusion that Mars' movement is erratic.

These apparent patterns caused by retrograde motion do not occur each evening. The patterns would appear if you charted Mars' position in our night sky over several months' time (during retrograde). Image Credit: NASA/JPL-Caltech

# data[].attributes.attachment_link.title
Mars Retrograde | Mars in our Night Sky - NASA's Mars Exploration Program

# data[].attributes.attachment_link.description
If you were to look up in the eastern sky at the same time each night and note where Mars appears to be compared to the constellations of stars, you would find the planet a little farther east with each viewing. That is, Mars appears to move from west to east from one night to the next.

# data[].attributes.attachment_link.readable_text
Mercury is the closest planet to the Sun and due to its proximity it is not easily seen except during twilight. For every two orbits of the Sun, Mercury completes three rotations about its axis and up until 1965 it was thought that the same side of Mercury constantly faced the Sun. Thirteen times a century Mercury can be observed from the Earth passing across the face of the Sun in an event called a transit, the next will occur on the 9th May 2016.

Facts about Mercury

Mercury does not have any moons or rings.

Mercury is the smallest planet.

Mercury is the closest planet to the Sun.

Your weight on Mercury would be 38% of your weight on Earth.

A solar day on the surface of Mercury lasts 176 Earth days.

A year on Mercury takes 88 Earth days.

It's not known who discovered Mercury.

A year on Mercury is just 88 days long.
One solar day (the time from noon to noon on the planet's surface) on Mercury lasts the equivalent of 176 Earth days while the sidereal day (the time for 1 rotation in relation to a fixed point) lasts59 Earth days. Mercury is nearly tidally locked to the Sun and over time this has slowed the rotation of the planet to almost match its orbit around the Sun. Mercury also has the highest orbital eccentricity of all the planets with its distance from the Sun ranging from 46 to 70 million km.

Mercury is the smallest planet in the Solar System.
One of five planets visible with the naked eye a, Mercury is just 4,879 Kilometres across its equator, compared with 12,742 Kilometres for the Earth.

Mercury is the second densest planet.
Even though the planet is small, Mercury is very dense. Each cubic centimetre has a density of 5.4 grams, with only the Earth having a higher density. This is largely due to Mercury being composed mainly of heavy metals and rock.

Mercury has wrinkles.
As the iron core of the planet cooled and contracted, the surface of the planet became wrinkled. Scientist have named these wrinkles, Lobate Scarps. These Scarps can be up to a mile high and hundreds of miles long.

Mercury has a molten core.
In recent years scientists from NASA have come to believe the solid iron core of Mercury could in fact be molten. Normally the core of smaller planets cools rapidly, but after extensive research, the results were not in line with those expected from a solid core. Scientists now believe the core to contain a lighter element such as sulphur, which would lower the melting temperature of the core material. It is estimated Mercury's core makes up 42% of its volume, while the Earth's core makes up 17%.

Mercury is only the second hottest planet.
Despite being further from the Sun, Venus experiences higher temperatures. The surface of Mercury which faces the Sun sees temperatures of up to 427°C, whilst on the alternate side this can be as low as -173°C. This is due to the planet having no atmosphere to help regulate the temperature.

Mercury is the most cratered planet in the Solar System.
Unlike many other planets which "self-heal" through natural geological processes, the surface of Mercury is covered in craters. These are caused by numerous encounters with asteroids and comets. Most Mercurian craters are named after famous writers and artists. Any crater larger than 250 kilometres in diameter is referred to as a Basin. The Caloris Basin is the largest impact crater on Mercury covering approximately 1,550 km in diameter and was discovered in 1974 by the Mariner 10 probe.

Only two spacecraft have ever visited Mercury.
Owing to its proximity to the Sun, Mercury is a difficult planet to visit. During 1974 and 1975 Mariner 10 flew by Mercury three times, during this time they mapped just under half of the planet's surface. On August 3rd 2004, the Messenger probe was launched from Cape Canaveral Air Force Station, this was the first spacecraft to visit since the mid 1970's.

Mercury is named for the Roman messenger to the gods.
The exact date of Mercury's discovery is unknown as it pre-dates its first historical mention, one of the first mentions being by the Sumerians around in 3,000 BC.

Mercury has an atmosphere (sort of).
Mercury has just 38% the gravity of Earth, this is too little to hold on to what atmosphere it has which is blown away by solar winds. However while gases escape into space they are constantly being replenished at the same time by the same solar winds, radioactive decay and dust caused by micrometeorites.

Mercury Diagrams

Mercury size compared to Earth

Mercury distance from the Sun and orbital eccentricity

# data[].attributes.attachment_link.title
Mercury Facts - Interesting Facts about Planet Mercury

# data[].attributes.attachment_link.description
Mercury is the closest planet to the Sun and due to its proximity it is not easily seen except during twilight. For every two orbits

# data[].attributes.attachment_link.readable_text
Expand your mind with these top eight facts about the planet Venus.

1. A day on Venus is longer than a year

It takes Venus longer to rotate once on its axis than to complete one orbit of the Sun. That's 243 Earth days to rotate once - the longest rotation of any planet in the Solar System - and only 224.7 Earth days to complete an orbit of the Sun.

2. Venus is hotter than Mercury - despite being further away from the Sun

Its mean temperature is 462°C. This is because of the high concentration of carbon dioxide in Venus' atmosphere, which works to produce an intense greenhouse effect. Heat is trapped in the atmosphere like a blanket, causing the temperature of the planet to be much higher than its proximity to the Sun would suggest.

3. Venus spins clockwise on its axis

Almost all planets in the Solar System spin anti-clockwise on their axis and orbit the Sun in an anti-clockwise direction. Venus also orbits the Sun anti-clockwise but spins clockwise on its axis. One theory for this unusual rotation is that it was knocked off its upright position earlier in its history! The only other planet in the Solar System to spin clockwise is Uranus.

Astronomers believe that at some point, a colliding celestial body tilted Venus so far off its original position that it is now upside down. The only other planet to spin in a weird direction is Uranus which spins on its side, probably the result of another collision early on in its life.

4. Venus is the second brightest natural object in the night sky after the Moon

The clouds of sulphuric acid in Venus' atmosphere make it reflective and shiny, obscuring our view of its surface. Its brightness makes it visible even during the day - if it's clear and you know where to look.

5. Venus has 90 times the atmospheric pressure of Earth

That's about the same as the pressure found at a depth of 1km in the Earth's oceans.

6. Venus is named after the Roman goddess of love and beauty

It is thought that Venus was named after the beautiful Roman goddess (counterpart to the Greek Aphrodite) due to its bright, shining appearance in the sky. Of the five planets known to ancient astronomers, it would have been the brightest.

7. Venus was the first planet to have its motions plotted across the sky, as early as the second millennium BC

Because Venus is easy to spot with the naked eye, it is impossible to say who discovered the planet. But over the centuries we have been able to measure Venus' motions, including the rare transit of Venus, when the planet appears to cross in front of the Sun.

8. We tend to say 'Venusian' not 'Venerian'

Following the rules of Latin, we should say 'venerean' as the adjective to describe things related to Venus. However, this is deemed to be too close to the word 'venereal'. The more commonly used word is 'Venusian' despite its clunky etymology.

# data[].attributes.attachment_link.description
Did you know that Venus is upside down? Expand your mind with these top eight facts about Venus, the planet.

# data[].attributes.attachment_link.readable_text
On Feb. 18, 2021, NASA's Mars Perseverance rover makes its final descent to the Red Planet. Here are some of the ways you can take part in this landing.

Now Through Landing

Lighting the Town Red:

If your city lights up red for landing, tag and share your photos using #CountdownToMars.

Feb. 16: Empire State Building
The iconic Empire State Building in New York City lit the tower red on Tuesday, Feb. 16 starting at sunset until 2 a.m.

Feb. 17: Chicago Skyline
Various buildings in Chicago light up red on Wednesday night, including the Adler planetarium.

Feb. 17-18: Terminal Tower in Cleveland, Ohio
Cleveland's landmark skyscraper will be lit up Mars red Wednesday and Thursday.

Feb. 17-19: Los Angeles International Airport
The light pillars at LAX will glow red from sundown on Wednesday, Feb. 17 through sunrise on Friday, Feb. 19.

Feb. 17-20: St. Louis Science Center
The McDonnell planetarium at the St. Louis Science Center in Missouri will feature a Martian glow through Feb. 20.

On Landing Day, Feb. 18:

After Landing:

Toolkit Resources

Related Links Helicopter Technology Demonstration

NASA Channels

# data[].attributes.attachment_link.title
Landing Toolkit: Perseverance Rover - NASA

# data[].attributes.attachment_link.description
One-stop shopping for everything you need to know about the upcoming landing of the Mars 2020 Perseverance rover.

# data[].attributes.body
Isaiah