Fifth Grade
Worksheets
Asteroids and Comets
Rocks fly through space all the time. Some of these rocks are asteroids; some are comets. What's the difference?
Asteroids are made up of rock and elements such as carbon or iron. They are similar to the rocky planets closest to the sun. Some asteroids are so large that scientists call them minor planets or planetoids. Like planets, some asteroids have moons.
There is an area in space called the asteroid belt. This belt exists between Mars and Jupiter. Millions of asteroids are found in the asteroid belt. The asteroid belt has an elliptical path, orbiting in the same direction as Mars and Jupiter.
The first asteroid was discovered in 1801; it is called Ceres. It is also the largest. Its circumference is about 960 kilometers. Ceres takes 4.6 Earth years to make one orbit around the sun.
