The Planet Quiz Show

Answer:  Pluto, Eris, and Ceres

Pluto, Eris (formerly 2003UB313), and Ceres (an asteroid) have been officially classified by the International Astronomical Union as dwarf planets. Currently, there are over 40 other known objects in our solar system which may one day bear the distinction of being classified as a dwarf planet. The number of dwarf planets may climb to as many as 2000 once our entire solar system is explored hundreds of years from now.

Eris is currently the largest dwarf planet in the solar system. It is approximately 1,550 miles in diameter. Pluto is 1,423 miles in diameter, and Ceres is 590 miles in diameter.

This is a painting by Pat Rawlings, of Science Applications International, showing New Horizons scheduled to arrive at the dwarf planet Pluto in 2015. The spacecraft was designed to be small, fast, and relatively cheap. New Horizons will pass several other Kuiper Belt objects on its way out of the solar system after first passing Pluto.