Rock In Space

Space. It's not just a cool place to explore -- it rocks. The rocks in space are sometimes called small bodies. Some of them are larger and are called minor planets or planetoids.
The three maintypes of space rocks are:
1. Comets
* Are the "dirty snowballs" of space. They are bodies of ice, rock, gas and dust.

2. Asteroids
* Are the oddballs of space. Mostasteroids are made of rock, but some are made of metals such as nickel and iron.

3. Meteoroids
* A chunk of rock in space, usually a piece of an asteroid or comet.
* What's thedifference between a meteoroid, meteor and meteorite?

Meteoroids | Meteor | Meteorite |
A small particle from an asteroid or comet orbiting the Sun | Is a streak of light that is caused by thefriction when a meteoroid from space enters the Earth's atmosphere. | Are space rocks that survive the friction of the atmosphere and land on Earth. |

Why Space Rocks?
NASA and other scientists studyspace rocks to help us learn about the origin of our solar system. Asteroids are thought to be the leftovers from the formation of the inner solar system, including Earth. Comets are thought to beleftovers from the formation of the outer planets.

Finding NEOs
NASA has missions to Near-Earth Objects. The Near-Earth Object Program will coordinate NASA-sponsored missions to find, track andclassify small bodies that could approach Earth. NEOs are the comets and asteroids whose orbits have been nudged into Earth's path by the gravity of nearby planets.

The Big Question: Will a NEO HitEarth?
We don't know when the next NEO impact will take place. But we can calculate the odds. By looking at the data of NEOs that we know about, we would be able to tell if it is going to enter Earth'spath decades before it would happen.

What happens in Arizona dessert?
This meteor crater in Arizona is thought to be the result of an asteroid hitting Earth 20,000-50,000 years ago.

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