How Long Does it Take Pluto to Orbit the Sun? | Universe Today

Written by Fraser Cain

Because Pluto orbits much further from the Sun than Earth, it takes much longer to orbit the Sun. In fact, Pluto takes 248 years to orbit the Sun. That's because Pluto orbits at an average distance of 5.9 billion km from the Sun, while Earth only orbits at 150 million km.

Pluto has a highly elliptical orbit. Its distance from the Sun varies from 4.4 billion km to 7.4 billion km. And during this orbital period, Pluto goes through a few interesting changes. You might be surprised to learn that Pluto has an atmosphere. When it's at its closest point to the Sun, Pluto's atmosphere evaporates from the surface and surrounding the dwarf planet. And then when it gets further away, the atmosphere freezes again, coating the surface in a thin layer.

Pluto was only discovered in 1930 by Clyde W. Tombaugh. Because it takes 248 years to orbit the Sun, Pluto won't have completed a full orbit until the year 2178.

We have written many articles about Pluto for Universe Today. Here's an article about why Pluto isn't a planet any more, and here's an article about methane discovered in Pluto's atmosphere.

If you'd like more information on Pluto, check out NASA's World Book on Pluto, and the Solar System Exploration Guide to Pluto.

We've also recorded several episodes of Astronomy Cast just about Pluto. Listen here, Episode 64: Pluto and the Icy Outer Solar System.

Filed under: Astronomy