# data[].attributes.attachment_link.description
Overview Pluto is a complex and mysterious world with mountains, valleys, plains, craters, and apparently even glaciers. Discovered in 1930, Pluto was long considered our solar system's ninth planet. But after the discovery that many similar, intriguing worlds inhabit the distant region beyond Neptune known as the Kuiper Belt, icy Pluto was reclassified as a [...]

# data[].attributes.attachment_link.title
Planet Venus: The deadliest Planet, Venus surface & Atmosphere [Naitional Geographic Channel, HD]

# data[].attributes.attachment_link.readable_text
Nearly 30 years after a NASA spacecraft visited the farthest planets in our solar system, Uranus and Neptune, the space agency is looking to go back.

Utilizing advancements in technology over the past 30 years, a NASA scientist and his team at the Goddard Space Flight Center in Greenbelt, Md. are dreaming up new instruments that could potentially explore the atmosphere of both planets. Uranus and Neptune are relatively unexplored, the space agency said, despite the fact that Voyager 2 snapped photos of both planets in 1986 and 1989, respectively.

"Available materials, filters, electronic detectors, flight computing, and data management and processing have all improved," Shahid Aslam, who is leading the team developing the next-gen flight hardware, said in a statement. "Frankly, we have better technology all the way around. It's clear that the time is now to develop the next generation of this instrument for future atmospheric entry probes."

NASA WANTS TO EXPLORE NEPTUNE'S MOON TRITON - SOLAR SYSTEM'S COLDEST OBJECT 'MAY HAVE OCEAN HARBORING ALIEN LIFE'
Aslam and his team want to create a new device similar to the net flux radiometer on board the Galileo mission that helped uncover Jupiter's atmosphere and adapt it to the atmospheric conditions of both the ice giants, which the researcher said would be important to the mission.

"Actually, you can learn a lot from net flux data, especially sources and sinks of planetary radiation," Aslam added

There are several differences between the proposed craft and device and the one that visited Jupiter. These include the use of thermopile sensors (able to convert heat or infrared wavelengths into electrical signals), infrared channels (to measure heat), additional viewing angles and a tighter field of view.

It's also likely that the device will be smaller and be able to support faster data sampling, Aslam said.

Right now, there are no formal plans to send a spacecraft to either Neptune or Uranus.

Even though both planets have not been studied to the length others have, such as Mars or Saturn, some information is known about them. They contain a "slushy mantle of water, ammonia, and methane ices, while their atmospheres consist of molecular hydrogen, helium, and methane gas." NASA added in its statement.

The color of the planets may be due to the level of methane in their atmospheres, but something else is causing the two planets' distinctive colors, Aslam added. Uranus appears as a "hazy blue-green" and Neptune is deep blue.
NASA MISSION FINDS ITS FIRST EARTH-SIZED ALIEN PLANET
In March, scientists at NASA JPL proposed a mission that would explore Neptune's largest moon, Triton, which some have theorized could have an ocean hiding underneath its surface.
CLICK HERE FOR THE FOX NEWS APP

# data[].attributes.attachment_link.title
NASA aims to probe mysterious atmospheres of Uranus and Neptune

# data[].attributes.attachment_link.description
Nearly 30 years after a NASA spacecraft visited the farthest planets in our solar system, Uranus and Neptune, the space agency is looking to go back. Utilizing advancements in technology over the past 30 years, a NASA scientist and his team at the Goddard Space Flight Center in Greenbelt, Md.

# data[].attributes.attachment_link.readable_text
Nearly 30 years after a NASA spacecraft visited the farthest planets in our solar system, Uranus and Neptune, the space agency is looking to go back.

Utilizing advancements in technology over the past 30 years, a NASA scientist and his team at the Goddard Space Flight Center in Greenbelt, Md. are dreaming up new instruments that could potentially explore the atmosphere of both planets. Uranus and Neptune are relatively unexplored, the space agency said, despite the fact that Voyager 2 snapped photos of both planets in 1986 and 1989, respectively.

"Available materials, filters, electronic detectors, flight computing, and data management and processing have all improved," Shahid Aslam, who is leading the team developing the next-gen flight hardware, said in a statement. "Frankly, we have better technology all the way around. It's clear that the time is now to develop the next generation of this instrument for future atmospheric entry probes."

NASA WANTS TO EXPLORE NEPTUNE'S MOON TRITON - SOLAR SYSTEM'S COLDEST OBJECT 'MAY HAVE OCEAN HARBORING ALIEN LIFE'
Aslam and his team want to create a new device similar to the net flux radiometer on board the Galileo mission that helped uncover Jupiter's atmosphere and adapt it to the atmospheric conditions of both the ice giants, which the researcher said would be important to the mission.

"Actually, you can learn a lot from net flux data, especially sources and sinks of planetary radiation," Aslam added

There are several differences between the proposed craft and device and the one that visited Jupiter. These include the use of thermopile sensors (able to convert heat or infrared wavelengths into electrical signals), infrared channels (to measure heat), additional viewing angles and a tighter field of view.

It's also likely that the device will be smaller and be able to support faster data sampling, Aslam said.

Right now, there are no formal plans to send a spacecraft to either Neptune or Uranus.

Even though both planets have not been studied to the length others have, such as Mars or Saturn, some information is known about them. They contain a "slushy mantle of water, ammonia, and methane ices, while their atmospheres consist of molecular hydrogen, helium, and methane gas." NASA added in its statement.

The color of the planets may be due to the level of methane in their atmospheres, but something else is causing the two planets' distinctive colors, Aslam added. Uranus appears as a "hazy blue-green" and Neptune is deep blue.
NASA MISSION FINDS ITS FIRST EARTH-SIZED ALIEN PLANET
In March, scientists at NASA JPL proposed a mission that would explore Neptune's largest moon, Triton, which some have theorized could have an ocean hiding underneath its surface.
CLICK HERE FOR THE FOX NEWS APP

# data[].attributes.attachment_link.title
NASA aims to probe mysterious atmospheres of Uranus and Neptune

# data[].attributes.attachment_link.description
Nearly 30 years after a NASA spacecraft visited the farthest planets in our solar system, Uranus and Neptune, the space agency is looking to go back. Utilizing advancements in technology over the past 30 years, a NASA scientist and his team at the Goddard Space Flight Center in Greenbelt, Md.

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

Facts about Neptune

It takes Neptune 164.8 Earth years to orbit the Sun. On 11 July 2011, Neptune completed its first full orbit since its discovery in 1846.

Neptune was discovered by Jean Joseph Le Verrier. The planet was not known to ancient civilizations because it is not visible to the naked eye. The planet was initially called Le Verrier after its discoverer. This name, however, quickly was abandoned and the name Neptune was chosen instead.

Neptune is the Roman God of the Sea. In Greek, Neptune is called Poseidon.

Neptune has the second largest gravity of any planet in the solar system - second only to Jupiter.

The orbit path of Neptune is approximately 30 astronomical units (AU) from the Sun. This means it is around 30 times the distance from the Earth to the Sun.

The largest Neptunian moon, Triton, was discovered just 17 days after Neptune itself was discovered.

Neptune has a storm similar the Great Red Spot on Jupiter. It is commonly known as the Great Dark Spot and is roughly the size of Earth.

Neptune also has a second storm called the Small Dark Spot. This storm is around the same size as Earth's moon.

Neptune spins very quickly on its axis. The planets equatorial clouds take 18 hours to complete one rotation. The reason this happens is that Neptune does not have a solid body.

Only one spacecraft, the Voyager 2, has flown past Neptune. It happened in 1989 and captured the first close-up images of the Neptunian system. It took 246 minutes - four hours and six minutes - for signals from Voyager 2 to reach back to Earth.

The climate on Neptune is extremely active. In its upper atmosphere, large storms sweep across it and high-speed solar winds track around the planet at up to 1,340 km per second. The largest storm was the Great Dark Spot in 1989 which lasted for around five years.

Like the other outer planets, Neptune possesses a ring system, though its rings are very faint. They are most likely made up of ice particles and grains of dust with a carbon-based substance coating them.

Neptune has 14 known moons. The largest of these moons is Titan - a frozen world which spits out particles of nitrogen ice and dust from below its surface. It is believed that Titan was caught by the immense gravitational pull of Neptune and is regarded as one of the coldest worlds in our solar system.

Neptune has an average surface temperature of -214°C - approximately -353°F.

More information and facts about Neptune

When scientific discoveries are made there is often a debate (sometimes heated) as to who deserves credit. The discovery of Neptune is one such example. Shortly after the discovery of the planet Uranus in 1781, scientists noticed that its orbit had significant fluctuations that were not expected. To solve this mystery, they proposed the existence of another planet whose gravitational field would account for such orbital variances.

In 1845, the English astronomer John Couch Adams completed his calculations as to the position of this unknown planet. Although he submitted his findings to the Royal Society (the leading English scientific organization), his work was met with little interest. However, a year later the French astronomer Jean Joseph Le Verrier made known his calculations that were strikingly similar to those of Adams. As a result of the two men's independent estimates being so close, the scientific community took notice and began its search for the planet in the region of the sky Adams and Le Verrier had predicted. On September 23, 1846, the German astronomer Johann Gall observed the new planet near to where Adam's calculations had forecasted and even closer to those of Le Verrier.

Le Verrier was initially given credit for the discovery. As a result, an international dispute arose, with one faction championing Adams and the other Le Verrier. This conflict, however, was not shared between the two men themselves. Eventually, the campaign for each side cooled, and both men were given credit.

Until the Voyager 2 spacecraft fly-by in 1989, little was known about Neptune. This mission provided new information about Neptune's rings, number of moons, atmosphere and rotation. Additionally, Voyager 2 discovered significant features of the moon Triton. There are no official planetary missions scheduled to Neptune in the near future.

Atmosphere

Neptune's upper atmosphere is composed of 80% hydrogen (H ₂), 19% helium and trace amounts of methane. Similar to Uranus, the blue coloration of Neptune is due in part to its atmospheric methane, which absorbs light having a wavelength corresponding to red. Unlike Uranus, Neptune is a deeper blue, and, therefore, some other atmospheric component must be present in the Neptunian atmosphere that is not found in Uranus' atmosphere.

Two significant weather patterns have been observed on Neptune. The first, seen during the Voyager 2 fly-by mission, are the Dark Spots. These are storms comparable to the Great Red Spot found on Jupiter. However, a difference between these storms is their duration. Whereas the Great Red Spot has lasted for centuries, the Dark Spots are much more shortly lived as is evident by their disappearance when Neptune was viewed by the Hubble Space Telescope just four years after the Voyager 2 fly-by.

The second of the two weather patterns observed by Voyager 2 is the swiftly moving white storm system, nicknamed Scooter. This type of storm system, which is much smaller than the Dark Spots, also appears to be short-lived.

As with the other gas giants, Neptune's atmosphere is divided into latitudinal bands. The wind speed achieved in some of these bands is almost 600 m/s, the fastest known in the Solar System.

Interior

The interior of Neptune, similar to that of Uranus, is made of two layers: a core and mantle. The core is rocky and estimated to be 1.2 times as massive as the Earth. The mantle is an extremely hot and dense liquid composed of water, ammonia and methane. The mantle is between ten to fifteen times the mass of the Earth.

Although Neptune and Uranus share similar interiors, they are, however, quite distinct in one way. Whereas Uranus emits only about the same amount of heat that it receives from the Sun, Neptune emits nearly 2.61 times the amount of the sunlight it receives. To place this in perspective, the two planets' surface temperatures are approximately equal, yet Neptune receives only 40% of the sunlight that Uranus does. Additionally, this large internal heat is also what powers the extreme winds found in the upper atmosphere.

Orbit & Rotation

With the discovery of Neptune, the size of the known Solar System increased by a factor of two. With an average orbital distance of , it takes sunlight almost four hours and forty minutes to reach Neptune. Moreover, this distance also means that a Neptunian year lasts about 165 Earth years!

Neptune's orbital eccentricity of .0097 is second smallest behind that of Venus. This small eccentricity means that the orbit of Neptune is very close to being circular. Another way of looking at this is to compare Neptune's perihelion of and its aphelion of and notice that this is a difference of less than two percent.

Like Jupiter and Saturn, Neptune rotates very quickly as compared to the terrestrial planets. With a rotational period of a little over 16 hours, Neptune has the third shortest day in the Solar System.

The axial tilt of Neptune is 28.3°, which is relatively close to the Earth's 23.5°. What is amazing is that, even at such a far distance from the Sun, Neptune still experiences seasons (though more subtly) similar to those on Earth as a result of its axial tilt.

Rings

Currently, Neptune is known to have thirteen moons. Of these thirteen only one is large and spherical in shape. This moon, Triton, is believed to have originally been a dwarf planet captured by Neptune's gravitational field, and, thus, not a natural satellite of the planet. Evidence for this theory comes from Triton's retrograde orbit of Neptune; that is, Triton orbits in the opposite direction that Neptune rotates. With a recorded surface temperature of -235° C, Triton is the coldest known object in the Solar System.

Neptune has three major rings - Adams, Le Verrier and Galle. This ring system is much fainter than that of the other gas giants. In fact, some of the rings are so dim that it was believed at one time that they were incomplete. However, images from the Voyager 2 fly-bys show extremely faint rings.

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

# data[].attributes.attachment_link.description
Size of Neptune compared with the Earth Facts about Neptune It takes Neptune 164.8 Earth years to orbit the Sun. On 11 July 2011, Neptune completed its first full orbit since its discovery in 1846. Neptune was discovered by Jean Joseph Le Verrier. The planet was not known to ancient civilizations because it is not ...

# data[].attributes.attachment_link.keywords[]
pluto's atmosphere could disappear by 2030

# data[].attributes.attachment_link.title
Winter is coming to destroy Pluto's atmosphere by 2030, study says

# data[].attributes.attachment_link.description
Pluto's atmosphere may completely collapse and freeze by 2030, according to a 28-year study of the small, cold dwarf planet on the edge of our solar system.

# data[].attributes.attachment_link.readable_text
Video Transcript

Imagine our solar system as a dance floor.

The planets are moving to pretty much the same rhythm.

But one of them is doing the side shuffle: the rebellious Uranus.

Just how different is Uranus's dance?

Very different.

While Earth's axis is tilted about 23 degrees, Uranus tilts almost 98 degrees!

Uranus' axis is so tilted, it actually looks like the planet is rotating on its side.

How did this all happen?

One theory is that a body the size of our Earth collided with Uranus a long time ago, radically throwing off its rotation.

Until we know for sure, the planet's strange tilt remains one of the great mysteries in the dance of the universe

And Uranus will keep doing the side shuffle like nobody's watching.

# data[].attributes.attachment_link.title
Student Video: Dancing Uranus | NASA/JPL Edu

# data[].attributes.attachment_link.description
In the dance of our solar system, one planet has moves like no other: Uranus. Find out how the planet's tilt puts it in a league all its own.

# data[].attributes.attachment_link.title
All About Uranus for Kids: Astronomy and Space for Children - FreeSchool

# data[].attributes.attachment_link.title
Living on Mercury - The Second Hottest Planet in the Solar System

# data[].attributes.attachment_link.title
NASA's Unexpected Discoveries on Jupiter | Juno

# data[].attributes.attachment_link.description
Overview Pluto is a complex and mysterious world with mountains, valleys, plains, craters, and apparently even glaciers. Discovered in 1930, Pluto was long considered our solar system's ninth planet. But after the discovery that many similar, intriguing worlds inhabit the distant region beyond Neptune known as the Kuiper Belt, icy Pluto was reclassified as a [...]

# data[].attributes.attachment_link.title
PLUTO AND BEYOND - A Traveler's Guide to the Planets | Full Documentary

# 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
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.title
NEPTUNE & URANUS - A Traveler's Guide to the Planets | Full Documentary

# data[].attributes.attachment_link.title
NEPTUNE & URANUS - A Traveler's Guide to the Planets | Full Documentary

# data[].attributes.attachment_link.readable_text
Saturn is the sixth planet from the Sun and the second-largest planet in our solar system. Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and helium. Saturn is not the only planet to have rings, but none are as spectacular or as complex as Saturn's. Saturn also has dozens of moons.

# data[].attributes.attachment_link.description
Introduction Saturn is the sixth planet from the Sun and the second-largest planet in our solar system. Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and helium. Saturn is not the only planet to have rings, but none are as spectacular or as complex as Saturn's.

# data[].attributes.attachment_link.title
VENUS & MERCURY - A Traveler's Guide to the Planets | Full Documentary

# data[].attributes.attachment_link.title
MARS - A Traveler's Guide to the Planets | Full Documentary

# data[].attributes.attachment_link.title
SATURN - A Traveler's Guide to the Planets | Full Documentary

# data[].attributes.attachment_link.title
Crashing Into Saturn: This Cassini Mission Is the Most Epic Yet | Short Film Showcase

# data[].attributes.attachment_link.readable_text
Venus is the second planet from the Sun and is Earth's closest planetary neighbor. It's one of the four inner, terrestrial (or rocky) planets, and it's often called Earth's twin because it's similar in size and density. These are not identical twins, however - there are radical differences between the two worlds.

Venus has a thick, toxic atmosphere filled with carbon dioxide and it's perpetually shrouded in thick, yellowish clouds of sulfuric acid that trap heat, causing a runaway greenhouse effect. It's the hottest planet in our solar system, even though Mercury is closer to the Sun. Surface temperatures on Venus are about 900 degrees Fahrenheit (475 degrees Celsius) - hot enough to melt lead. The surface is a rusty color and it's peppered with intensely crunched mountains and thousands of large volcanoes. Scientists think it's possible some volcanoes are still active.

Venus has crushing air pressure at its surface - more than 90 times that of Earth - similar to the pressure you'd encounter a mile below the ocean on Earth.

Another big difference from Earth - Venus rotates on its axis backward, compared to most of the other planets in the solar system. This means that, on Venus, the Sun rises in the west and sets in the east, opposite to what we experience on Earth. (It's not the only planet in our solar system with such an oddball rotation - Uranus spins on its side.)

Venus was the first planet to be explored by a spacecraft - NASA's Mariner 2 successfully flew by and scanned the cloud-covered world on Dec. 14, 1962. Since then, numerous spacecraft from the U.S. and other space agencies have explored Venus, including NASA's Magellan, which mapped the planet's surface with radar. Soviet spacecraft made the most successful landings on the surface of Venus to date, but they didn't survive long due to the extreme heat and crushing pressure. An American probe, one of NASA's Pioneer Venus Multiprobes, survived for about an hour after impacting the surface in 1978.

More recent Venus missions include ESA's Venus Express (which orbited from 2006 until 2016) and Japan's Akatsuki Venus Climate Orbiter (orbiting since 2016).

NASA's Parker Solar Probe has made multiple flybys of Venus. On Feb. 9, 2022, NASA announced the spacecraft had captured its f irst visible light images of the surface of Venus from space during its February 2021 flyby.

As Parker Solar Probe flew by Venus in February 2021, its WISPR instrument captured these images, strung into a video, showing the nightside surface of the planet. Credit: NASA/APL/NRL

In June 2021, three new missions to Venus were announced. NASA announced two new missions, and ESA announced one:

VERITAS: NASA's VERITAS, or Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy, will be the first NASA spacecraft to explore Venus since the 1990s. The spacecraft will launch no earlier than December 2027. It will orbit Venus, gathering data to reveal how the paths of Venus and Earth diverged, and how Venus lost its potential to be a habitable world.

DAVINCI: NASA's DAVINCI mission will launch in the late 2020s. After exploring the top of Venus's atmosphere, DAVINCI will drop a probe to the surface. On its hour-long descent, the probe will take thousands of measurements and snap up-close images of the surface. The probe may not survive the landing, but if it does, it could provide several minutes of bonus science.

EnVision: ESA has selected EnVision to make detailed observations of Venus. As a key partner in the mission, NASA is providing the Synthetic Aperture Radar, called VenSAR, to make high-resolution measurements of the planet's surface features.

Go Farther

Everything you need to know about Venus.

Venus In Depth

Ten Things to Know About Venus
Pop Culture

Because it's so bright and easy to see in the sky, Venus has played a role in popular culture since ancient times, inspiring writing and song:

It was called the most beautiful star in the sky by Homer, author of "The Iliad" and "The Odyssey" - two of the oldest and most important works in Greek literature.

More recently, Venus became a popular venue for 20th-century science fiction writers, including Edgar Rice Burroughs ("Pirates of Venus," 1934); Arthur C. Clarke ("Before Eden," 1961); and C.S. Lewis ("Perelandra," 1943).

Australian author Shirley Hazzard won the 1980 National Book Critics Circle Award for fiction with her book, "The Transit of Venus," about two orphaned sisters. American author John Gray used the planet and its masculine counterpart to explain relationships in his 1992 book "Men Are From Mars, Women Are From Venus."

A song called "Venus" was teen idol Frankie Avalon's first No. 1 hit when it topped the Billboard Hot 100 chart in 1959. A decade later, a different song called "Venus" by the Dutch rock band Shocking Blue topped the charts in several countries. In 1986, British pop group Bananarama had a No. 1 hit in the U.S. with their cover of the song.

More recently, Venus has been a backdrop for video games such as Transhuman Space, Battlezone, and Destiny. And in the Disney animated film "The Princess and the Frog," Ray the firefly falls in love with Venus, "the evening star," as he has mistaken it for another firefly.

Kid-Friendly Venus

Read More

Read More

# data[].attributes.attachment_link.description
Venus is the second planet from the sun and our closest planetary neighbor.

# 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
Mercury is the closest planet to the Sun but, perhaps surprisingly, it does not have the highest temperatures. It is the second densest planet of the Solar System, but also the smallest planet. The structure of Mercury makes it the most similar planet to Earth.
Key Facts & Summary

Since Mercury can be seen without the need of a telescope, many ancient civilizations saw the planet, and as such it is impossible to determine who discovered it first. However, it was first observed with the help of a telescope in early 17th century, by Galileo Galilei.

Galileo's crude telescope didn't manage to capture Mercury's phases, this would be observed later by astronomer Giovanni Zupi in 1639, and thus he discovered that the planet had similar phases like Venus and the Moon.

In ancient times, Mercury was taught as being two different objects in the sky: The Mourning Star and The Evening Star. In Venus's case, it was also mistakenly believed to be two different things.

Venus spends most of its time away from Earth. This paradoxically makes Mercury the closest planet to Earth, a plurality of the time.

Mercury was named after the Roman messenger god, because of its fast movements around the Sun.

Mercury is the closest planet to the Sun at a distance of 57.91 million kilometers / 35.98 miles or 0.4 AU away. It takes sunlight 3.2 minutes to travel from the Sun to Mercury.

Despite its closeness to the Sun, it is not the hottest planet, that title belongs to Venus but Mercury is the fastest planet, completing a trip around the Sun in 88 Earth days. This also makes one year on Mercury the equivalent of 88 Earth days, the shortest year of any planet.

It orbits around the Sun with a speed of about 29 miles or 47 kilometers per second.

Despite being the smallest terrestrial planet from the Solar System, and in fact the smallest of all the planets, it is the second densest planet in the Solar System, with a density of 5.43 g/cm³.

For a comparison, Mercury's size is about a third of Earth, and Earth has a density of 5.51 g/cm³.

Mercury has a radius of 2.439 km or 1516 mi, and a diameter of 4.879 km or 3.032 mi.

Mercury's axis has the smallest tilt of any of the Solar System's planets at about ​¹⁄₃₀ degrees, while its orbital eccentricity is the largest of all known planets in the Solar System.

Mercury's distance from the Sun is only about two-thirds or 66%, of its distance at aphelion, at its aphelion it is 0.44 AU away from the Sun.

At its closest distance or perihelion, it is 0.30 AU away from the Sun.

Mercury spins slowly on its axis and completes one rotation every 59 Earth days. One Mercury solar day or one full day-night cycle, equals 176 Earth days-just over two years on Mercury. (Reminder, one year on Mercury is 88 Earth days)

Mercury does not have any known satellites or ring systems.

Its surface is very similar to Earth's Moon, implying that the planet hasn't been geologically active for many years.

Instead of an atmosphere, Mercury possesses a thin exosphere made up of atoms blasted off the surface by the solar wind and striking meteoroids. Mercury's exosphere is composed mostly of oxygen, sodium, hydrogen, helium and potassium.

Temperatures on the surface of Mercury are both hot and cold. During the day, temperatures on the surface can reach up to 800 degrees Fahrenheit / 430 degrees Celsius. Because the planet has no atmosphere to retain that heat, nighttime temperatures on the surface can drop to -290 degrees Fahrenheit / -180 degrees Celsius. These changes in temperature are the most drastic in the entire Solar System.

Mercury's magnetic field is offset relative to the planet's equator. Though the magnetic field at the surface has just 1.1% the strength of Earth's, it interacts with the magnetic field of the solar wind to sometimes create intense magnetic tornadoes that funnel the fast, hot solar wind plasma down to the surface of the planet.

Mercury rotates in a way that is unique in the Solar System. It is tidally locked with the Sun in a 3:2 spin-orbit resonance.

Mercury and Venus orbit the Sun within Earth's Orbit, this makes them inferior planets.

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 14 th century BC. The name used in these tablets is translated as "the jumping planet".

Some Babylonian records date back to the 1 st millennium BC. They called the planet Nabu, after the messenger to the gods in their mythology. The ancient Greeks knew the planet as Hermes while the Romans named it Mercury and it remained as such to this day.

Credits cannot be given to a single civilization or person because the planet has always been easy to spot on the sky. What we can do is to give credit to those who first studied the planet by more "modern" means such as Galileo Galilei in the early 17 th century, and Giovanni Zupi who in 1639, observed that the planet had phases just like Venus and the Moon.

Formation

It is theorized that Mercury was formed about 4.5 billion years ago when gravity pulled swirling gas and dust together to form the small planet. Its small size but enormous core is theorized to be the result of a collision with another giant object that stripped much of its surface.

Distance, Size and Mass

Mercury is the closest planet to the Sun, at a distance of 57.91 million kilometers / 35.98 miles or 0.4 AU away. It takes sunlight 3.2 minutes to travel from the Sun to Mercury.

Mercury has a radius of 2.439 km or 1516 mi, and a diameter of 4.879 km or 3.032 mi. It is about the size of the continental United States, slightly bigger. It has a mass of about 3.285 × 10^23 kg or about 5.5% that of Earth.

Despite being the smallest planet from the Solar System, it is the second densest planet in the Solar System, with a density of 5.43 g/cm³ after Earth. For comparison, Mercury's size is about a third of Earth, and Earth has a density of 5.51 g/cm³.

Orbit and Rotation

Mercury's highly eccentric, egg-shaped orbit takes the planet as close as 29 million miles or 47 million kilometers, and as far as 43 million miles or 70 million kilometers from the Sun. It takes a trip around the Sun every 88 days thus 1 orbit/year is the equivalent of 88 Earth days. Mercury travels through space at nearly 29 miles or 47 kilometers per second, faster than any other planet.

The diagram above illustrates the effects of the eccentricity, showing Mercury's orbit overlaid with a circular orbit having the same semi-major axis. The resonance makes a single solar day on Mercury last exactly two Mercury years, about 176 Earth days.

Radar observations in 1965 proved that the planet has a 3:2 spin-orbit resonance, rotating three times for every two revolutions around the Sun. The eccentricity of Mercury's orbit makes this resonance stable at perihelion, when the solar tide is strongest. The Sun is nearly still in Mercury's sky. The orbital eccentricity of Mercury in simulations varies chaotically, from zero or circular to more than 0.45 over millions of years because of the perturbations of the other planets.

More accurate modeling based on a realistic model of tidal response has demonstrated that Mercury was captured into the 3:2 spin-orbit state at a very early stage of its history, within 20 or 10 million years after its formation.

Mercury spins slowly on its axis and completes one rotation every 59 Earth days. But when Mercury is moving fastest in its elliptical orbit around the Sun, and it is closest to the Sun, each rotation is not accompanied by a sunrise and sunset like on most other planets. The morning Sun appears to rise briefly.

It then sets and rises again from some parts of the planet's surface. The same thing happens in reverse at sunset for other parts of the surface. Mercury travels in an elliptical orbit slowing down when it's farther from the Sun, and accelerating as it draws closer.

Axial tilt

The axial tilt is almost zero, with the best measured value as low as 0.027 degrees. This is significantly smaller than that of Jupiter, which has the second smallest axial tilt of all planets at 3.1 degrees. On average, Mercury is the closest planet to Earth, and to each of the other planets in the Solar System.

Surface and Geology

Very similar in appearance to Earth's moon, Mercury's surface is scarred by many impact craters from comets or meteoroids. Interestingly, many of these craters are named after famous deceased artists and authors. There are also extensive mare-like plains present and the craters also indicate that the planet has been geologically inactive for billions of years.

It is believed that Mercury was heavy bombarded by comets and asteroids during and shortly after its formation 4.6 billion years ago, as well as during a possibly separate subsequent event called the Late Heavy Bombardment that ended 3.8 billion years ago.

During this bombardment, Mercury's entire surface suffered even more because of its lack of atmosphere that would have slowed impacts down. It is believed that Mercury was volcanically active during this period.

Basins such as the Caloris Basin were filled with magma, producing smooth plains similar to the lunar marias found on the Moon.

The largest known crater is Caloris Basin, with a diameter of 1,550 km or 963 miles. About 15 impact basins have been identified on Mercury, with more to be revealed.

Two geologically distinct plains regions on Mercury have been identified. Gently rolling, hilly plains the regions between craters are Mercury's oldest visible surfaces, predating the heavily cratered terrain.

These crater plains appear to have obliterated many earlier craters. Unlike lunar maria, the smooth plains of Mercury have the same albedo as the older inter-crater plains. Another interesting feature of Mercury's surface is the numerous compression folds or rupes that crisscross plains. A theory suggests that as Mercury's interior cooled, it contracted and its surface began to deform, creating wrinkle ridges and lobate scarps associated with thrust faults. These features have indicated that Mercury's radius became smaller, shrinking in the range of 1 to 7 km or 4 miles.

Other factors indicate that this shrinking and geological activity may be present to this day. The volcanic system on Mercury is quite complex, though its exact age is hard to pinpoint but it is speculated to be billions of years old.

Temperatures on the surface of Mercury are both hot and cold. During the day, temperatures on the surface can reach up to 800 degrees Fahrenheit / 430 degrees Celsius. Because the planet has no atmosphere to retain that heat, nighttime temperatures on the surface can drop to -290 degrees Fahrenheit / -180 degrees Celsius. These changes in temperature are the most drastic in the entire Solar System.

Structure

Mercury is a terrestrial planet having three main layers: a core, mantle and crust. Mercury's crust has no tectonic plates and its iron core is enormous, making up 85% of the planets radius while Earth's inner and outer core, account for about 55%.

Because of the core's unusual size, it influences Mercury's overall size by causing it to shrink. The iron core has slowly cooled and contracted for about 4.5 billion years. By doing this, it pulled the surface inward, and thus has reduced the planet's size between 1 - 7 km or 4 miles.

The planet consists of about 70% metallic and 30% silicate material leading to its high density and thus placing it as the second densest planet. It is believed that if the effects of the gravitational compression were to be factored out from both Mercury and Earth, Mercury would take the first place as the densest.

This density also indicates that its core is huge and rich in iron. Mercury's crust is estimated to be around 35 km or 22 mi thick.

Atmosphere - Exosphere

Because of its proximity to the Sun, Mercury's gravity is strongly affected. It is too small and hot for its gravity to retain any significant atmosphere over long periods of time. The surface temperature of Mercury ranges from 100 to 700 K (−173 to 427 °C; −280 to 800 °F) at the most extreme places but it never rises above 180 K at the poles, due to the absence of an atmosphere and a steep temperature gradient between the equator and the poles.

Thus Mercury does not have an atmosphere, but it does have a thin exosphere. The exosphere is traditionally the outermost layer of a planet's atmosphere. Mercury's exosphere is made up of oxygen, sodium, hydrogen, helium and potassium that are all whipped up from the planet's surface by the solar winds.

Although the daylight temperature at the surface of Mercury is generally extremely high, observations strongly suggest that ice / frozen water, exists on Mercury. The floors of deep craters at the poles are never exposed to direct sunlight, and temperatures there remain below 102 K, far lower than the global average.

Water ice strongly reflects radar, and observations by the 70-meter Goldstone Solar System Radar and the VLA in the early 1990s revealed that there are patches of high radar reflection near the poles. Although ice was not the only possible cause of these reflective regions, astronomers think it was the most likely.

Magnetosphere

Even if it is small and has a slow 59-day-long rotation, Mercury has a significant and apparently global magnetic field. It has been estimated that this magnetic field has 1.1% the strength of Earth's. The strength at its equator is about 300 nT, and like that of Earth's it is dipolar. The difference is that Mercury's poles are nearly aligned with the planet's spin axis.

It is speculated that the magnetic field is generated by a dynamo effect, similar to the magnetic field of Earth. This effect would be resulted from the circulation of the planet's iron-rich liquid core. Particularly strong tidal effects caused by the planet's high orbital eccentricity would serve to keep the core in the liquid state necessary for this dynamo effect.

The magnetic field is strong enough to deflect the solar wind around the planet, creating a magnetosphere. It interacts with the magnetic field of the solar wind to sometimes create intense magnetic tornadoes that funnel the fast, hot solar wind plasma down to the surface of the planet.

Life Habitability

Extreme temperatures both cold and hot make it unlikely that life may develop there. The temperatures and solar radiation that characterize this planet are most likely too extreme for organisms to adapt to.

Satellites

Mercury doesn't have any known satellites even though many objects much smaller than Mercury have. It is believed that moons form in the same time as their parent planets and in the case of Mercury, all the materials around it were used up by the planet leaving almost nothing left so that a moon could be formed.

Another theory suggests that Mercury couldn't have a moon because of its closeness to the Sun. Because of this, the Sun's greater gravity force would overcome that of Mercury and pull any objects around it, towards itself. Overall, Mercury's closeness to the sun prevents it from ever having a satellite.

Future plans for Mercury

Because of Mercury's closeness to Earth, it will always be a target for missions and further observations. The third spacecraft set to arrive on Mercury is called BepiColombo, and it is planned to arrive at Mercury in 2025.

Did you know?

- From the surface of Mercury, the Sun would appear more than three times as large as it does when viewed from Earth, and the sunlight would be as much as seven times brighter.

- NASA's spacecraft Mariner 10 was the first mission to explore Mercury in 1974-1975.

- NASA's spacecraft MESSENGER was the first to orbit Mercury in 2008.

- Mercury's apparent distance from the Sun as viewed from Earth never exceeds 28°.

- You could fit approximately 21,253,933 Mercuries inside the Sun.

- In ancient China, Mercury was known as "the hour Star" - being associated with the direction of the north.

- Modern Chinese, Korean, Japanese and Vietnamese cultures refer to the planet as "water star."

- Hindu mythology used the name "Buddha graha" to refer to Mercury. This god was thought to preside over Wednesday.

- The god Odin or Woden of Germanic paganism was associated with the planet Mercury and also Wednesday.

- Maya people may have represented Mercury as an owl that served as a messenger to the underworld.

- Mercury can, like several other planets and the brightest stars, be seen during a total solar eclipse.

- Even though Mercury is a planet, it is even smaller than the largest natural satellites in the Solar System: Ganymede and Titan, albeit Mercury is more massive.

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

- Your weight on Mercury would be 38% of your weight on Earth as Mercury has a gravity of 3.7 m/s², while Earth has 9.807 m/s².

- The most cratered planet in the solar system is Mercury.

- NASA has mapped the entire surface of Mercury.

- It is believed that Mercury has a tail: it streams of particles sloughing off its surface.

- The naming and discovery of Mercury cannot be attributed to anyone.

- The crater Caloris Basin is large enough to fit in the state of Texas.

- 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.

- Mercury is about 50% larger in diameter than Earth's Moon.

- It would take about 18 Mercury's to match Earth.

- Mercury doesn't experience any seasons.

- It is one of the most popular planets in our imagination.

- Mercury is about twice as large as Pluto.

[1.] Wikipedia

[1.] https://upload.wikimedia.org/wikipedia/commons/d/d9/Mercury_in_color_-_Prockter07-edit1.jpg

[2.] https://www.universetoday.com/35960/size-of-the-planets/

[3.] https://en.wikipedia.org/wiki/File:ThePlanets_Orbits_Mercury_PolarView.svg

[4.] https://en.wikipedia.org/wiki/File:Mercury%27s_orbital_resonance.svg

[5.] https://en.wikipedia.org/wiki/File:Unmasking_the_Secrets_of_Mercury.jpg

[6.] https://en.wikipedia.org/wiki/File:PIA19450-PlanetMercury-CalorisBasin-20150501.jpg

[7.] https://en.wikipedia.org/wiki/Caloris_Planitia#/media/File:The_Mighty_Caloris_(PIA19213).png

[8.] https://en.wikipedia.org/wiki/Inter-crater_plains_on_Mercury#/media/File:Rudaki_CW0131770591G_web.png

[9.] https://en.wikipedia.org/wiki/File:Mercury%27s_internal_structure1.jpg

[10.] https://en.wikipedia.org/wiki/File:PIA19421-Mercury-Craters-MunchSanderPoe-20150416.jpg

[11.] https://en.wikipedia.org/wiki/File:North_pole_of_Mercury_-_NASA.jpg

[12.] https://en.wikipedia.org/wiki/File:Merc_fig2sm.jpg

[13.] https://en.wikipedia.org/wiki/File:Mercury_Magnetic_Field_NASA.jpg

# data[].attributes.attachment_link.title
Mercury | Facts, Information, History & Definition

# data[].attributes.attachment_link.description
Mercury is the closest planet to the Sun but, perhaps surprisingly, it does not have the highest temperatures. It is the second densest planet of the Solar System, but also the smallest planet. The structure of Mercury makes it the most similar planet to Earth.

# data[].attributes.attachment_link.title
Mars, the red planet: Facts and information

# data[].attributes.attachment_link.description
The rusty world is full of mysteries—and some of the solar system’s most extreme geology. Learn more about Earth’s smaller, colder neighbor.

# data[].attributes.attachment_link.description
NASA's real-time portal for Mars exploration, featuring the latest news, images, and discoveries from the Red Planet.

# data[].attributes.attachment_link.keywords[]
insight mission catches martian sunrise and sunset - cnn

# data[].attributes.attachment_link.title
InSight mission catches Martian sunrise and sunset

# data[].attributes.attachment_link.description
NASA's stationary InSight lander is spending two years on Mars learning everything it can about the deep interior of the Red Planet. But it's also providing us with cool details like a daily Martian weather report and, now, a glimpse of what it looks like when the sun rises and sets on Mars.

# data[].attributes.attachment_link.readable_text
This page provides a brief description of each of the planets (and links to dwarf planets) of our solar system. You can also find out about the difference between planets, dwarf planets and small solar system bodies (SSSBs) here.

Planet Formation

The planets and the solar system were formed from a huge cloud of gases and dust particles left over when a massive star exploded as a supernova.

The gas drifted in space and it's thought that another supernova explosion nearby may have caused a pressure wave to pass through the cloud that caused clumping to occur. As the matter clumped together, gravity in that area got stronger which attracted more matter which in turn increased the gravitational pull. As more and more matter fell toward the high density area, due to conservation of momentum it began to spin - rather like water going down a plug hole. The result was that as the gravity intensified, the spin became faster resulting in a flat disk of gas and dust surrounding a central high density sphere of gas.

Gravity was also working within the disk of rotating gas and dust pulling matter together to form primitive planets within the gas disk.

Eventually the temperature and pressures in the central sphere became so high that the atoms began fusing together (nuclear fusion) and the Sun ignited producing heat and light and also the solar wind - an out streaming of subatomic particles.

The heat of the Sun and the solar wind immediately began to have an effect on the huge cloud of gas and particles in the disk. Volatile substances such as water ice near the Sun would heat and sublimate into gas, and these and other gases such as hydrogen would be gently accelerated away from the Sun by the solar wind.

At the distance of Jupiter, the temperature the Sun was not high enough to cause water ice to evaporate and so this meant that large quantities of solid material were available to build larger planets. These planets could therefore attract and keep hold of more of gas from the gas disk. This is one theory as to why the gas giants became so large, and why there is a divide in planet size between the small inner rocky planets and the outer gas giants.

As time continued, the workings of gravity and the solar wind eventually resulted in the solar system becoming as we know it today. A mostly empty space with eight surviving planets, five dwarf planets, a band of possibly millions of asteroids. All of this is thought to be surrounded by a cloud of icy comets - preserved remains of that early dust from which the solar system formed.

Planets and Dwarf Planets in Order from the Sun

The planets and dwarf planets are listed here in the order they are from the Sun. Click for more information on each.

# data[].attributes.attachment_link.title
Planets of our Solar System :: The Planets Today

# data[].attributes.attachment_link.description
This page provides a brief description of each of the planets (and links to dwarf planets) of our solar system. You can also find out about the difference between planets, dwarf planets and small solar system bodies (SSSBs) here.

# data[].attributes.attachment_link.title
Outer Space: "We are the Planets," The Solar System Song by StoryBots | Netflix Jr

# data[].attributes.attachment_link.description
Until the end of the 20th century, ours was the only planetary system known. We now know of more planets outside our solar system than within it. Astronomers have now located more than 1,000 planets orbiting stars other than our own, and the latest observations are starting to reveal what these planets are like.

# data[].attributes.attachment_link.description
Our solar system can be divided into three regions: the inner solar system, the outer solar system, and the Kuiper Belt and Oort Cloud. The inner, rocky planets are Mercury, Venus, Earth, and Mars. These worlds also are known as terrestrial planets because they have solid surfaces. Mercury, Earth, a…

# data[].attributes.attachment_link.title
Discovery Education | Your Daily Learning Platform

# data[].attributes.attachment_link.description
Discovery Education inspires educators to go beyond traditional learning with award-winning digital content and professional development. Learn more today!

# data[].attributes.attachment_link.readable_text
Attention Educator Member Teachers! Go to our special offers page for information about attractive upcoming professional development events next year. Not an Educator Member? Join Today!
Check out resources from our Affiliates!

Global locations of visitors using this page right now

The new Community Earth System Model will allow scientists to study climate change in more detail than ever before ... Read more

Clouds are an important part of Earth's weather and climate. Scientists use computer models to study our planet's climate ... Read more

Try out some inexpensive, hands-on magnetism activities. Hands-on activities help learners gain a intuitive grasp of the complexities of magnetic fields ... Read more

Archimedes was a Greek mathematician and engineer who lived between 287-212 B.C. His greatest contributions are in the field of geometry and in the development of war machines ... Read more

Neptune is an ice giant planet; smaller than the gas giants Jupiter and Saturn but much larger than Earth. Neptune has more than a dozen moons and a faint ring system. It is the 8th planet from the Sun ... Read more

# data[].attributes.attachment_link.description
Explore the Earth and space sciences and related arts and humanities connections with Windows to the Universe! Earth, planets, moons, the Sun, and the stars. Astronomy, Mythology, images, video, interactives, teacher resources, and classroom activities. Spanish and English, differentiated learning.

# data[].attributes.attachment_link.description
This is a collection of many of the best images from NASA's planetary exploration program. The collection has been extracted from the interactive program "Welcome to the Planets" which was distributed on the Planetary Data System Educational CD-ROM Version 1.5 in December 1995. It has also been updated with the addition of more recent images.

# data[].attributes.attachment_link.title
What Exists Within the Reaches of Our Solar System?

# data[].attributes.attachment_link.description
Learn more about the celestial bodies that exist within our solar system.