What Are Asteroids?
An asteroid is a large rock in outer space. Some, like Ceres, can be very large, while others are as small as a grain of sand. Due to their smaller size, asteroids do not have enough gravity to pull themselves into the shape of a ball. Astronomers group asteroids into different categories based on the way they reflect sunlight.
Asteroid Belt
The asteroid belt is divided into an inner belt and an outer belt. The inner belt which is made up of asteroids that are within 250 million miles (402 million km) of the Sun, contains asteroids that are made of metals.
The outer belt, which includes asteroids 250 million miles (402 million km) beyond the Sun, consists of rocky asteroids. These asteroids appear darker than the asteroids of the inner belt, and are rich in carbon.
How many asteroids are there?
26 very large asteroids have been discovered, which is probably most of the big ones. But there are still millions of smaller ones that we have yet to see because they are too tiny, only a mile or so across.
Link:
http://www.kidsastronomy.com/asteroid.htm
An asteroid is a large rock in outer space. Some, like Ceres, can be very large, while others are as small as a grain of sand. Due to their smaller size, asteroids do not have enough gravity to pull themselves into the shape of a ball. Astronomers group asteroids into different categories based on the way they reflect sunlight.
Asteroid Belt
The asteroid belt is divided into an inner belt and an outer belt. The inner belt which is made up of asteroids that are within 250 million miles (402 million km) of the Sun, contains asteroids that are made of metals.
The outer belt, which includes asteroids 250 million miles (402 million km) beyond the Sun, consists of rocky asteroids. These asteroids appear darker than the asteroids of the inner belt, and are rich in carbon.
How many asteroids are there?
26 very large asteroids have been discovered, which is probably most of the big ones. But there are still millions of smaller ones that we have yet to see because they are too tiny, only a mile or so across.
Link:
http://www.kidsastronomy.com/asteroid.htm