The Answer:

Pluto is the only planet in our solar system which has not been visited by a spacecraft, and until it is, our knowledge of it is limited. With that said, astronomers have pieced together a very low-resolution image of the planet. It appears to be mostly brown, perhaps resulting from frozen methane.

On January 16, 2006, NASA launched the New Horizons mission to Pluto and the Kuiper Belt. It is expected to make its closest approach to Pluto in July 2015. Check out its site for much more information on the mission and the planet.

—The Editors