Found in between Mars and Jupiter, many asteroids are made up of rocks and left over metal. They have a dusty layer of shattered rock on their cratered surfaced, and they can be as big as 567 miles in diameter.
Ceres, the biggest asteroid, is round. However, asteroids can have odd, non-round shapes because their gravitational force is not strong enough to pull material into spherical shapes. Asteroids that could cross over or hit Earth are potentially dangerous. If an asteroid were to hit the Earth, it would create hazards like forest fires, tidal waves, and clouds of dust that could block sunlight for months. In the past, asteroids have hit Earth and caused problems like these. The most dangerous example occurred 65 million years ago. It led to a change in the Earth’s climate, which caused the dinosaurs to become extinct.
Scientists also study asteroids to learn about the solar system’s early history. The Near Earth Asteroid Rendezvous (NEAR) spacecraft visited the asteroid, Eros, in 2000 to study it, for example. And the Japanese asteroid explorer, Hayabusa, brings back rock samples from asteroids for researchers to examine.
Asteroids are rocks from space that have the ability to make a big impact on Earth. Studying them gives many people jobs and answers. Studying asteroids is also important for the safety of the Earth!
[Source: Children’s Atlas of the Universe, NASA]