The Asteroid Belt is a region between the inner planets and outer planets where thousands of asteroids are found orbitting around the Sun.

More than 7000 asteroids have been discovered. Several hundred more are discovered each year. There are undoubtedly hundreds of thousands more that are too small to be seen from the Earth.

The Galileo spacecraft photographed Ida and Gaspra on its way to Jupiter. They are the only asteroids which have been studied closely.

Recently, the NEAR mission flew by an asteroid named Mathilde on June 27, 1997, and returned many images. NEAR will be visiting the Eros asteroid in January 1999.

The largest asteroid by far is Ceres. It is 914 km across and contains about 25% of the mass of all the asteroids combined! The next largest are Pallas, Vesta and Hygiea which are between 400 and 525 km across. All other known asteroids are less than 340 km across.

Vesta has been studied recently with the Hubble Space Telescope.

Though they are rarely visible with the naked eye, many asteroids are visible with binoculars or small telescopes.