Day 1 2 Background 2.1 Cosmology 2.1.12 Student Overview Day 2

Pluto

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


Pluto, usually the ninth planet from the Sun, is the smallest planet in the solar system. Some scientists believe that Pluto once was one of  Neptune's moons. It pulled out of Neptune's atmosphere and made its own orbit.


Basic Facts

 

Pluto

Earth

Position from the Sun

9 (usually)

3

Diameter

1,430 miles (2,300 km)

7,926 miles (12,753 km)

Moons

1

1

Rings

0

0

Average Distance from Sun

3,666,000,000 miles (5,900,000,000 km)

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

Your Weight on the Planet

Multiply your weight by 0.03

Multiply your weight by 1.0

Length of One Year

248 Earth years

1 Earth year

Length of One Day

6 Earth days and 9 hours

1 Earth day

What?s in the Atmosphere?

Nitrogen, carbon monoxide

Nitrogen, oxygen

Temperature

-370?F (-220?C)

-128?F to 136?F

(-89?C to 58?C)


Discovery

After the discovery of Neptune in 1846, scientists believed that there still might be a ninth planet, and they set out to find it. Finding Pluto was difficult. Pluto is very small, it is a long way from the Sun, and it is very dim in the sky. The planet moves very slowly, taking 248 years to complete its orbit around the Sun, so it took many years before Pluto?s motion could help identify it. An amateur American astronomer, Clyde Tombaugh, finally found Pluto in 1930.


Missions to Pluto

Pluto is the only planet that has not been visited by a spacecraft from Earth. The Pluto Express probe has been delayed.


Interesting Facts About Pluto


Pluto, usually the ninth planet from the Sun, is the smallest planet in the solar system. Some scientists believe that Pluto once was one of Neptune's moons. It pulled out of Neptune's atmosphere and made its own orbit.


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