What is an Asteroids? | Types, Definition, Structure, Function & Facts
What is an Asteroid?
An asteroid is a piece of rock and metal in space that orbits the Sun. Asteroids range in size from a few feet to hundreds of miles.
Most asteroids are not round, but are lumpy and potato-shaped. In orbit around the Sun, they tumble and spin.
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Types of Asteroids
There are three main types of asteroids based on the type of element that makes up the asteroid. The main categories include carbon, rock, and metal.
Carbon – Carbon-containing asteroids are also known as carbon-containing asteroids. They consist mainly of carbon-rich rocks. They are very dark in color. About 75% of all asteroids are of the carbon type.
Stony – Stony asteroids are also known as siliceous asteroids. They are made mainly of stone and some metal.
Metallic – Metallic asteroids are primarily made of metals, mainly iron and nickel. They usually contain a small amount of rock mixed in.
Asteroid Belt
Most asteroids orbit the Sun in a belt called the asteroid belt. The asteroid belt lies between the planets Mars and Jupiter. You can think of it as a belt between the rocky planets and the gaseous planets. There are millions upon millions of asteroids in the asteroid belt.
Largest Asteroids
Some asteroids are so large that they are considered asteroids. The four largest asteroids are Ceres, Vesta, Pallas and Hygiea.
Ceres – Ceres is by far the largest asteroid. It is so large that it is classified as a dwarf planet. Ceres is 597 miles in diameter and contains about a third of the total mass of the asteroid belt. It is named after the Roman goddess of the harvest.
Vesta – Vesta is 329 miles in diameter and is considered an asteroid. Vesta is larger than Pallas, but slightly smaller. It is the brightest asteroid seen from Earth and is named after the Roman goddess of the house.
Pallas – Pallas is the second asteroid discovered after Ceres. It is the largest non-circular object in the solar system. It is named after the Greek goddess Pallas Athena.
Hygiea – Hygiea is the largest carbon-like asteroid. It is named after the Greek goddess of health. It measures about 220 miles wide 310 miles long.
Trojan Asteroids
There are other asteroid groups outside the asteroid belt. One major group are the Trojan asteroids. Trojan asteroids share an orbit with a planet or moon. However, they do not collide with the planet. Most Trojan asteroids orbit the sun along with Jupiter. Some scientists think there could be as many Trojan asteroids as there are asteroids in the belt.
Could an Asteroid hit Earth?
Well, not only can an asteroid hit the Earth but many asteroids have hit the Earth before. These asteroids are called near-Earth asteroids, and they have orbits that bring them close to Earth. It is estimated that an asteroid more than 10 feet in diameter hits Earth about once a year. These asteroids typically explode when they hit the Earth’s atmosphere and cause little damage to the Earth’s surface.
Interesting Facts about Asteroids
Italian astronomer Giuseppe Piazzi discovered the first asteroid, Ceres, in 1801.
The word asteroid comes from the Greek word meaning “star-shaped”.
Scientists estimate that there are more than a million asteroids more than a kilometer in diameter in the asteroid belt.
The five largest asteroids account for more than 50% of the total mass of the asteroid belt.
Some scientists have speculated that the extinction of the dinosaurs was caused by the collision of a large asteroid with Earth.