Question: What is nebula

Angus Cook answered on 23 Jun 2016:

A nebula is the name we give to a large collection of gasses and ‘cosmic dust’ (not made up of the same stuff as you get in your house, but a similar idea) out in space.

They can be a place where stars are created, because some of the gas can start to clump together and attract more and more gasses. Eventually the mass of the gas gets so great that it forces some of the gas right in the middle together, and starts a process called ‘nuclear fusion’. This is the reaction which releases heat and light from start (and is going on in our own Sun right now).

Smaller ones can also be formed when a star ‘dies’ (i.e. it used up all its hydrogen, and then helium fuel). The collection of gas and dust this time comes from the outer layers of the star and it chucks out large quantities of matter. We think this will eventually happen to our own Sun and solar system, we’ll become a ‘planetary nebula’.

They can look like this, so that’s not a bad end to our solar system 🙂