Day 1 2 Background 2.1 Cosmology 2.1.12 Student Overview Day 2

Neptune

Mercury ] Venus ] Mars ] Jupiter ] Saturn ] Uranus ] Neptune ] Pluto ] 


Neptune, usually the eighth planet from the Sun, is a very cold place. Occasionally, Pluto crosses Neptune's orbit and becomes the eighth planet. Its bluish color comes from its atmosphere of methane gas.


Basic Facts

 

Neptune

Earth

Position from the Sun

8 (usually)

3

Diameter

30,800 miles (49,500 km)

7,926 miles (12,753 km)

Moons

8

1

Rings

4

0

Average Distance from Sun

2,799,000,000 miles (4,504,000,000 km)

93,000,000 miles (149,000,000 km)

Your Weight on the Planet

Multiply your weight by 1.2

Multiply your weight by 1.0

Length of One Year

165 Earth years

1 Earth year

Length of One Day

17 hours and 6 minutes

24 hours

What’s in the Atmosphere?

Hydrogen, helium, methane

Nitrogen, oxygen

Temperature

-350ºF (-210ºC)

-128ºF to 136ºF

(-89ºC to 58ºC)


Discovery

Neptune wasn't discovered the way all the other planets in our solar system were found. Astronomers didn't scan the sky with their powerful telescopes to find Neptune. They used math instead!

After the discovery of Uranus, astronomers were having trouble figuring out Uranus’ orbit. They realized that there must be another planet farther out than Uranus because this unknown planet’s gravitational pull slightly changes Uranus' orbit. They were right! French astronomer Leverrier and English astronomer John Couch Adams made the mathematical calculations of where Neptune should be in 1843, and German astronomer Johann Galle found it in 1846.


Missions to Neptune

Mission

Launch Date

Mission Accomplishments

Voyager 2 (USA)

August 20, 1977

Took thousands of pictures of Neptune, its rings, and its moons.


Interesting Facts About Neptune


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