Asteroid Belt example essay topic

Asteroids Sixty-Five million years ago, 70 percent of life on Earth died. The most reasonable and possible reason this happened was an asteroid. An asteroid hit the Earth very hard, and in doing this, dirt and dust from the impact stayed in the air and it blocked out sunlight, that's why the dinosaurs died. An asteroid is a rock from outer space. Asteroids have orbited the Sun along with the planets since the solar system formed about 4.6 billion years ago, but it's only been 200 years since we first discovered them. Meteorites are small pieces of asteroids broken off on impact with other asteroids.

Most meteorites are rusty brown on the outside, have rounded edges from melting as they go through Earth's atmosphere, and contain iron. There are 3 different types of meteorites: stony, metallic, and stony metallic. 92 percents of all asteroids are stone, 6 percent are made of iron and nickel, and the rest are a combination. Some meteorites also contain gold, copper, platinum, and carbon. Scientists get a good idea of what asteroids are made of by studying them through telescopes. They can tell what an asteroid is made of by the color and brightness of the asteroid.

A lot of asteroids that we have discovered are very dark and made of stone, but there are shiny ones that are made of nickel and iron. Most big asteroids are ball shaped. Smaller asteroids, which are usually broken off of a larger asteroid, come in a lot of different shapes. All asteroids have craters that form when they bump or crash into other asteroids.

The older the asteroid, the more times it has been hit and the more craters it has. Asteroids can be found orbiting the Sun in a belt between Mars and Jupiter; this is called the Asteroid belt or Main belt. The asteroid belt has been said to probably contain millions of asteroids that are all different. There are more than 20,000 numbered asteroids. Some times asteroids get knocked off the asteroid belt.

As asteroids revolve around the Sun in elliptical orbits, Jupiter's gravity and getting to close to Mars or another asteroid can change an asteroids path, this could send an asteroid out of the asteroid belt and into space across the orbits of other planets. An example of asteroid orbits changing is Mar's moons Phobos and Deimos. These were asteroids that went to close to Mars and got caught in its orbit. Right now, a 22-mile wide asteroid called Eros is in an orbit that is close to Earth's orbit. Eros is twice the size of the asteroid that killed the dinosaurs.

Eventually, Earth will be in Eros's path. This asteroid could kill all life on Earth if it hits us. All scientists can do right now is study it to learn if there is anyway to avoid it, or get rid of it. Not all asteroids are as dangerous as this one. Most of the time they float around harmlessly in space. Asteroids don't hit each other a lot.

Asteroid belts aren't like in the movies where the asteroids are very close. They can sometimes be millions of miles away. Even though scientists call asteroids "minor plants", they are very different that planets. Asteroids are much smaller than planets and are shaped differently. Most asteroids do not have enough gravity to pull them into regular spheres, so instead of being shaped like a grapefruit, they are shaped like a potato. Asteroids come in a variety of sizes and shapes just like potatoes.

The largest asteroid we know of right now is Ceres. Ceres could almost cover an area the size of Alaska. Ceres is 578 miles across. Astronomers have found about 200 asteroids that are wider than 62 miles. Some asteroids contain water, carbon and other things that are necessary to support life. There is a theory that asteroids that were carrying water carbon and other things to support life, brought these to Earth billions of years ago, and started life on Earth.

One of the things I learned about asteroids on this project is that some have moons. On 1993 in August, the space probe Galileo flew past an asteroid named Ida. It took a few close pictures and scientists looked at the pictures and discovered that there was a moon orbiting around Ida. The scientists named this moon Dactyl. Now scientists think many asteroids have moons.

I believe this because it's the way gravity works. Even though asteroids do seem harmless, each person has a 1 in 20,000 chance of dying from a natural disaster like asteroids, hurricanes, tornados, earthquakes, and floods.

Bibliography

"Asteroids"- By Samantha Bonar " The Three Big Bangs"- By Philip Dauber " Comets, Asteroids and Meteorites"- By Cynthia Nicolson web.