The Solar System: Dwarf Planets

Some of you, the older ones especially, will be wondering: "What about Pluto, I thought that it was the last planet in our soloar system?" Well Pluto is now be desribed as a Dwarf Planet.

A Dwarf Planet is a celestial body that:

• is in orbit around the Sun
• has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a nearly round shape
• has not cleared the neighbourhood around its orbit
• is not a satellite

Pluto is the largest dwarf planet in the solar system (see the picture on the right) followed by Eris, Makemake, Haumea, with the smallest being Ceres - found in the asteroid belt.

The Solar System page 13