​1. ​Space Bodies. ​​​

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PLANET​S

Astronomers agree about two things.​

To be a planet, an object must orbit​ a star. If it orbits something else, like another planet, it​ is a moon instead.​

The second point is that the object must be big enough​ that gravity makes it into a sphere. Many asteroids and​ comets have odd shapes. They are definitely not planets. 

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STARS

Stars are the luminous bodies of the universe, they produce light because they are burning due to nuclear reactions. Groups of stars make patterns in the night sky. These are called constellations. Examples: Centaur, Great Bear, Orion...

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​SATELLITES

They are bodies orbiting around a planet like the Moon.

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COMETS

They are tiny bodies made of ice, dust and gas. They travel around the Sun. When approaching the sun, part of its nucleus vaporizes to form a gaseous coma and a long luminous tail.

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ASTEROIDS

Asteroids are small rocky bodies orbiting around  the sun , but  they are too small to be called planets.

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​METEOROIDS

Meteoroids are small bodies that travel through space. They are smaller than asteroids. They come from broken asteroids or from the moon, other comets or Mars. ​

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METEORS

A meteor is a meteoroid that has entered the Earth's atmosphere.

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METEORITES

Meteorites are meteors that have fallen to the Earth's surface. 

 

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