Neptune: Size, distance from the Sun, orbit

Neptune has 13 moons; the two largest are Triton and Nereid.
By | Published: October 20, 2023 | Last updated on November 3, 2023

Gemini Sparkle

Key Takeaways:

  • Voyager 2 captured images of Neptune, revealing features such as the Great Dark Spot and Scooter, a bright, fast-moving cloud, at a distance of 4.4 million miles.
  • Neptune's physical characteristics include a diameter of 31,000 miles, an orbital period of 165 Earth years, a rotational period of 16 Earth hours, and an atmospheric composition primarily of hydrogen, helium, and methane.
  • Neptune's average temperature is -370°F (-220°C), and its escape velocity is 52,600 mph (84,700 km/h).
  • Neptune possesses six narrow rings, thirteen moons (with Triton and Nereid being the largest), and was discovered in 1846 by Johann Galle and Heinrich D'Arrest.
Key takeaways sponsored by The Space Store
Neptune
This picture of Neptune was produced from the last whole-planet images taken through the green and orange filters on the Voyager 2 narrow-angle camera. The images were taken at a range of 4.4 million miles from the planet, 4 days and 20 hours before closest approach. The picture shows the Great Dark Spot and its companion bright smudge near the center of the image. On the west limb the fast moving bright feature called Scooter and the little dark spot are visible. These clouds persisted as long as Voyager’s cameras could resolve them.
NASA / JPL
Size: Neptune is slightly smaller than Uranus and has a diameter of 31,000 miles (50,000 kilometers), so about 4 Earths would fit across its face.
Distance from the Sun: Neptune is the eighth planet from the Sun. It orbits at an average distance of 2.8 billion miles (4.5 billion km), thirty times farther than Earth.Orbit around the Sun: It takes 165 Earth years for Neptune to go around the Sun one time.

Rotation: It takes Neptune only 16 Earth hours for it to spin on its axis once.

Surface: Like the other gas-giant planets, Neptune’s “surface” is the top of its deep atmosphere. This contains hydrogen (79 percent), helium (18 percent), and methane (3 percent), which gives the planet its blue color. Neptune’s atmosphere has a striped pattern like both Jupiter’s and Saturn’s.

Temperature: The average temperature at Neptune is –370° F
(–220° C).
Escape velocity: To escape Neptune’s gravity, you need to travel 52,600 miles (84,700 km) per hour, compared to 25,000 miles (40,200 km) per hour necessary to escape Earth’s gravity.Other information: Six narrow rings encircle Neptune. Because some places have more particles than others, Neptune’s rings form arcs around the planet.

Johann Galle and Heinrich D’Arrest discovered Neptune in 1846.

Neptune has 13 moons, the two largest are Triton and Nereid. Triton is made of rock and ice. Its surface is rich in water ice, dry ice, frozen carbon monoxide, methane, and nitrogen. Triton has cold geysers that spit nitrogen instead of the hot water that geysers on Earth release.

Neptune was the Roman god of the oceans.

You can get more facts on the planets in our solar system in each of the articles linked to below:

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