A nebula is a big cloud of gas and dust in space. There are lots of different types of nebulae. Some nebulae come from old dying stars that explode and spread their gas over a large region of space.
Member picture of the Rosette nebula (Credit: J M Dean)
Often nebulae are regions where new stars are formed. We call these stellar nurseries because they contain lots of young stars. Astronomers think that the Sun was created in a nebula over 4.5 billion (4,500,000,000) years ago!
The main gas that makes up most nebulae is hydrogen.
NASA/Hubble picture of NGC3918
The galaxy below on the left is called the Andromeda Galaxy! It is a nearby spiral galaxy that we think looks like our galaxy. If Andromeda wasn’t so dim it would appear much larger than the Moon in our night sky! The galaxy below on the right is the Whirlpool Galaxy and consists of the remnant of two galaxies than have collided!
