Wednesday, April 1, 2015
A is for Asteroids
Asteroids which are also called space rocks orbit the sun in the asteroid belt which is located between Mars and Jupiter. Most asteroids are small. The total mass of the asteroids in the asteroid belt is less than half the total mass of Earth's moon. There are asteroids which are located outside of the asteroid belt.
The largest asteroid is named Ceres which is 583 miles wide. The smallest asteroid is named 1991 BA and is 20 miles wide. Some asteroids are spherical while others are irregularly shaped.
If an asteroids strikes the Earth, it is called a meteorite. There are two types of meteorites: those which are composed of iron and those which are composed of stone. Iron meteorites are 91% iron, 8.5% nickel and 0.6% cobalt. Stony meteorites 36% oxygen, 26% iron, 18% silicon, 14% magnesium, 1.5% aluminum, 1.4% nickel and 1.3% calcium.
If they are large meteorites can be dangerous. A meteorite which was 65 miles wide exploded over the Siberia section of Russia injuring 1200 people.