Nebulae

 Nebula are clouds of dust and gas found in space. Often defined by four different categories, dark, emission, reflection and planetary. They are essential for the birth of new stars.  

At one quarter the diameter of the earth, the moon is a natural object that orbits the earth. 

Star clusters are large groups of stars bound together under gravity. There are two types, open  and globular.

Our solar system consists of the Sun, planets, natural satellites (moons), comets, asteroids and more. 

The universe contains trillions of other galaxies in various shapes and sizes. Astronomers classify them by their shape. These are spiral, barred spiral, irregular, peculiar, elliptical and lenticular.