ASTEROIDS, COMETS & METEORS

asteroids

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The things that asteroids are made of are rocky and/or iron-nickel material. Most of them are found in an orbit between Jupiter and Mars. Most asteroids have craters inside them that are left from colliding with other objects in space.
Some asteroids have other asteroids orbiting them. One example is Asteroid Ida and its moon Dactyl (look at the picture).

COMETS

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Comets are believed to be in long elliptical (not in a perfect circle) orbits. These orbits can take them beyond the orbit of Uranus to around the Sun. They can be found in the Kuiper Belt between Uranus and the Oort Cloud from beyond Pluto.

The word 'comet' itself comes from the Greek meaning "long-haired" because of their tails. Throughout human history, people thought comets bring bad luck. The truth is, they are just natural wonders of the solar system.

The nucleus of a comet is kind of like a ball of rock and dirty snow. As comets get closer to the sun, the frozen gases and dust begin to heat and cause vaporized gases, dust, debris to flow behind them in a long tail. As everything melts, a cloud of gases and dust forms a coma. The nucleus and coma together are the head of the comet. Because of the comet's orbit we can see it come back from time to time. For example, Halley's Comet can be seen about every 76 years.


meteors

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Meteors, which are also known as shooting stars, can have different sizes; from as small as a grain of sand, to the size of a softball. As a meteor enters the atmosphere of the Earth it becomes very hot because of friction. You can also feel friction when you rub your hands; it feels warm. They become very bright and they look like they are flying across the sky.

Sometimes the Earth can enter a meteoroid stream that's left by a comet and it makes a meteor shower. These showers can be predicted. They come about every year. They're named after constellations that the meteors appear to be coming from. This is how they come during the year: Lyrids - April and June; Perseids - August; Orionds - October; Taurids - November; Leonids - November.

These showers sometimes have more than 100 meteors and they are very cool to watch. If you have watched them and you didn't feel comfortable, you can easily lie on the ground so that you don't feel any neck strain.

The meteors that survive going through the atmosphere, which causes heat and friction, and hit the ground are called meteorites. Scientists worldwide collected about 10,000 meteorites for studying. Meteorites are made up of parts called Breccia, Carbonaceous Chondrites, Chondrites and Chondrules.
When an asteroid hits the Earth and it's big enough, it can make an enormous crater.

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This is a sample of a meteorite.
We hope you learned something from our section about Asteroids, Meteors and Comets.

Sincerely,

JAKUB LIČKO and CHIKA NAKAHARA

Source: http://www.kidscosmos.org/kid-stuff/asteroid-facts.html