Neptune Facts – The Ultimate Guide to Neptune

Neptune the blue frozen planet is the eighth planet from the Sun and the last known planet in our solar system. Discover fascinating Neptune facts about the atmospheric structure to why Neptune is named after the Roman god of the seas. 

Contents show

Neptune Facts

  • Neptune is the most distant known planet.
  • Neptune is the smallest of the four gas giants.
  • Neptune has a ring system similar to those of Uranus.
  • Neptune has 14 moons
  • Neptune’s has a surface gravity very similar to Earth’s.
  • Neptune is named for the Roman god of the sea.
  • Only one spacecraft has visited Neptune.
  • Neptune has the strongest words in the solar system.
  • The temperature on Neptune is the coldest in the solar system.
  • A year on Neptune lasts 165 Earth years.
  • One day on Neptune is only sixteen hours

Neptune Orbit & Rotation

In this section, we’ll explore Neptune orbit and rotation. There is a lot to learn about the eighth planet in our solar system before you can take on the role of an astronomy expert.

How Long Does It Take Neptune to Orbit the Sun

Neptune has the longest orbital period of any planet in our solar system, orbiting the Sun once every 60,190 Earth days (164.8 years).

How Far From the Sun Does Neptune Orbit

Neptune is the furthest planet from the Sun with an average distance of 4.5 billion kilometers. This is so far away that it takes sunlight four hours to reach Neptune from the Sun.

How Long Does It Take For Neptune To Rotate on Its Axis

Neptune rotates once about its axis once every sixteen hours.

How Long Is a Year on Neptune

Neptune takes 165 times as long to circle the Sun as does the Earth, making one year on Neptune 60,190 Earth days long.

How Long Is a Day on Neptune 

One day on Neptune is only sixteen hours, two-thirds as long as a day on Earth.

Neptune History

Neptune, the smallest planet out of the four gas giants, has a lot of history that can be learned by an amateur astronomer. The following questions will detail some of these things for you to enjoy learning about.

How Old Is Neptune

Neptune was formed at the same time as the other planets in our solar system, roughly 4.5 billion years ago. Interestingly, Neptune likely came together closer to the Sun than the planet’s current orbit, migrating outward as the gaseous protoplanetary disc accreted.

How Did Neptune Get Its Name

Neptune is named for the Roman god of the sea, but this was only accepted after many other names were proposed, including Janus, Oceanus, and Le Verrier’s planet (after its discovering scientist). Neptune was decided upon to follow the convention of every planet but Earth being named after either Greek or Roman gods.

Who Discovered Neptune

While Galileo Galilei appears to have plotted observations of Neptune as early as 1612, its movement was too slight to have been detected by his small telescope, and he thought it was likely a star of some kind. Neptune’s discovery was ultimately attributed to Urbain Le Verrier in 1846. This was the first time a planet was discovered via mathematical modeling, with Le Verrier predicting Neptune’s location more accurately than his competitors’ models.

How Many Spacecrafts Have Visited Neptune

NASA’s Voyager 2 is the only spacecraft to have visited Neptune. Voyager 2 flew as close as 3,000 km to Neptune’s north pole (August 25, 1989) during its Grand Tour of the solar system.

Atmospheric Structure and Dynamics of Neptune 

Neptune is the eighth planet from the sun and it has a diameter of 30,700 kilometers. Neptune’s mass is 17 times that of Earth. The atmosphere on Neptune consists mainly of hydrogen, helium, methane, and ammonia.

The atmospheric structure and dynamics of Neptune are complex due to its fast rotation rate. There are two main wind belts: one in each hemisphere with winds blowing at up to 1300 km/hr near the equator. We find many more Neptune facts about the atmospheric structure and dynamics below.

Does Neptune Have Rings

While much more difficult to observe than Saturn’s brilliantly reflective rings, Neptune does have its own ring system similar to those of Uranus.

How Many Rings Does Neptune Have

Neptune has at least five rings of which we’re currently aware, and it also has four arcs, portions of rings that stay clumped together due to the gravitational effects of Neptune’s moon Galatea. The main rings are named Adams, Arago, Lassell, Leverrier, and Galle. The arcs are: Liberté, Egalité, Fraternité, and Courage.

What Are Neptune’s Rings Made Out Of

Neptune’s rings consist of 20-70% micrometer size dust, and the rest is small rocks. This composition leaves the rings dark and hard to see.

Does Neptune Have Moons

Like the other gas giants, Neptune has many natural satellites.

How Many Moons Does Neptune Have

Fourteen known moons orbit Neptune. The largest, Triton, is the only large moon in the solar system with a retrograde orbit (circles its planet opposite to the planet’s rotation), suggesting it was most likely an independent object captured by Neptune’s gravity.

What Are the Names of Neptune Moons

Neptune, being named for the god of the sea, has its moons also named for Greek and Roman water gods. 

The fourteen moons are: Triton, Proteus, Despina, Thalassa, Larissa, Naiad, Nereid, Halimede, Galatea, Neso, Sao, Laomedeia, Psamathe, and Hippocamp. Triton, Proteus, Despina, and Thalassa were the children of Poseidon. Larissa was one of Poseidon’s lovers. Naiad and Nereid were minor Greek water deities, and Hllimede, Galatea, Neso, Sao, Laomedeia, and Psamathe were specific Nereids. Hippocamp is named after a mythical half-horse half-fish creature.

What Is Neptune’s Great Dark Spot

Neptune’s Great Dark Spot was a large, oval storm discovered in 1989 in Neptune’s southern hemisphere. This was apparently a transient phenomenon, as it has since disappeared.

Is the Great Dark Spot still on Neptune?

Neptune’s Great Dark Spot has disappeared since its initial discovery in 1989, but other storms have appeared in its stead.

What causes the Great Dark Spot on Neptune?

The Great Dark Spot on Neptune was a storm likely caused by the strongest sustained winds on any planet in the solar system. Recorded speeds as high as 2,100 km/h drive the swirling gases into turbulent weather patterns.

How many dark spots does Neptune have?

Neptune currently has two storms on its surface large enough to create dark spots visible by Earth observations. The larger one is wider than the Atlantic Ocean, and a slightly smaller one appeared momentarily when the larger one made a U-turn at the equator. The Hubble telescope has observed four transient dark spot storms since it started watching Neptune in 1993.

How Big Is Neptune

Neptune is roughly four times wider than the Earth with a diameter of 49,244 kilometers across.

What Is the Diameter of Neptune

Neptune has a diameter of 49,244 kilometers across, roughly four times that of Earth.

What Is Neptune Made of

Neptune is an ice giant, one of two in our solar system. As such, it consists primarily of a dense fluid of icy water, methane, and ammonia, circling a small, rocky core.

What Is Neptune Atmosphere Made of

Neptune’s atmosphere is an icy mix of water, methane, and ammonia. The prominence of methane gives Neptune its blue color. Current theories also suggest an ocean of superheated water under Neptune’s clouds kept from boiling away due to incredibly high pressures.

How Much Gravity Is on Neptune

The surface gravity on Neptune is 11.15 m/s2, only 1.14 times that on Earth.

What Is the Temperature Range on Neptune

The temperature range on Neptune is extraordinarily wide due to a combination of its size and distance from the Sun. Without solar heating, Neptune’s outer atmosphere is one of the coldest places in our solar system with cloud top temperatures as low as -218 Celsius, but the temperatures at its high-pressure center can reach 5,100 C. This gives Neptune a temperature range of 5,318 C.

What Is the Weather Like on Neptune

Neptune is the windiest world in our solar system. Winds of frozen methane speed across the planet at more than 2,000 km/h, five times faster than the most powerful winds ever recorded on Earth (400 km/h).

Does Neptune Rain Diamonds

Astronomers and physicists have suspected for nearly 40 years that it rains diamonds deep within Neptune’s atmosphere. These diamond crystals are made of decomposing methane, and similar phenomena are suspected to exist on Jupiter, Saturn, and Uranus.

Is There Water On Neptune

There is water on Neptune and lots of it. Water makes up a large part of the icy materials swirling about its rocky core, and current theories suggest there may be a super hot ocean underneath Neptune’s frigid clouds, kept in place with high pressure.

What Color Is Neptune

Neptune is a blue planet due to the high amounts of methane in its atmosphere.

Can We Live on Neptune

Due to Neptune not having much of a solid surface like other gas giant planets in our system it would be near impossible to live on Neptune. However, Neptunes largest moon Triton is thought to be more likely to become a space colony.

Can You Land on Neptune

As Neptune is a gas giant there is not much of a solid surface that we could land on. It would be impossible for a spacecraft to land on the surface of Neptune without sinking into the body of the planet. 

Comparing Neptune and Distances From Other Planets 

We here at backyard stargazers. We love to present information and facts about astronomy to our audience. In this section, we will be discussing the distances from Neptune and other planets in orbit around the sun.

How Far Is Neptune From Earth

The distance from one planet to another is constantly shifting because both bodies are moving through space. When Neptune and Earth line up on the same side of the sun, at their closest they are only 2.7 billion miles (4.3 billion kilometers) apart – that’s about 30 times closer than when they’re furthest away!

How Big Is Neptune Compared to Earth

Neptune is 4 times wider than Earth, with a radius of 24.622 km, and from an average distance, it’s about 30 astronomical units away from the sun. If you were to shrink earth down into what would be its size on Neptune (a nickel), that little planet would still be as big as your baseball!

How Long Does It Take to Get to Neptune

Voyager 2’s 12-year journey is the longest and fastest of any spacecraft. It zoomed past Neptune at an incredible 42,000 miles per hour!

How Many Earths Can Fit in Neptune

57 Earths is an incredible number, and for a comparison that’s 57.7 times the volume of Earth! You could fit 57 planets inside Neptune with room to spare; it has a surface area of 7.64 x 109 km2

How Far Is Neptune From the Sun

The distance from Neptune to the Sun, 2.8 billion miles (4.5 billion kilometers), is 30 astronomical units away. One AU can be defined as a unit of measurement for measuring distances in space: it’s how far Earth is from the sun and 4 hours would take our light signal traveling at 186,300 mph all that way!

How Big Is Neptune Compared to the Moon

The mass of Neptune is 1.02 x 1026 kg or 102 quadrillion metric tons! That’s 17 times more than the Earth and enough to make a few hundred thousand elephants combined.