Asteroids are primoridal objects left over from the formation of the Solar System. Many of the asteroids in our solar system are located in an area between Mars and Jupiter known as the Asteroid Belt. It is believed that the chunks of metal and rock that make up the belt were actually a failed terrestrial planet that was trying to form but was unable to merge together because of the strong gravitational pull of Jupiter.

The belt contains millions of asteroids. The asteroids in the asteroid belt come in a variety of sizes. Although many are very small. If all of the asteroids were combined into a ball, they would still be much smaller than Earth’s moon. More than half the mass of the main belt is contained in the four largest objects: Ceres, 4 Vesta, 2 Pallas, and 10 Hygiea.

The first asteroid from the belt to have been discovered was Ceres. Sicilian astronomer Father Giuseppe Piazzi spotted Cere in 1801. Ceres was initially classified as a planet and later classified as an asteroid. It is now designated as a dwarf planet along with Pluto and Eris. Ceres comprises 25 percent of the asteroid belt’s total and is approximately 590 miles across, about the size of Texas.

The asteroid material is so thinly distributed that multiple unmanned spacecraft have traversed it without incident. The first spacecraft to make a journey through the asteroid belt was Pioneer 10 in 1972.

Asteroid Belt Facts

  • The belt is not like the asteroid fields in movies; these asteroids are very far apart.
  • Asteroids are small Solar System bodies that orbit the Sun made of rock and metal.
  • Most asteroids are covered in dust called regolith.