Nebulas are interstellar clouds that are formed by gas and dust clouds that orbit with the stars around our galaxy. Hydrogen makes up an enormous 71% of these gas clouds, and helium makes up 21%. The rest is just made up of dust and other elements. These clouds consist of solid microscopic particles of silicates, carbon, and iron compounds. Interstellar gas is typically -10,000 degrees fahrenheit. At that temperature the atoms and molecules in a gas move too slowly to generate much pressure. Due to the fact that the atoms are moving so slowly the gas might not have enough pressure to support itself against gravity. This can result in the gas forming clusters. These clusters are gas clouds that that collapse because of a collision with another gas cloud or other occurrences. Maps that have been made by radio telescopes show that gas clouds are not in uniform. They can embody clumps that are smaller and denser than other clumps. When a dense clump collapses it breaks up creating multiple stars, to be created by one gas cloud. Which explains why stars that are grouped together tend to be the same age. Astronomers believe that the transformation from gas cloud to a star takes place in several stages. In the first stage a dense clump in a cloud heats up and collapses. In the second stage the dense object starts to spin taking the shape of a disc. After around a million years the disk like object forms into a protostar. After that a star forms a main sequence star and so on. But the entire life cycle of a star starts in a nebula.