Science glossary film: Nebula

A cloud of gas and dust in space. The term originally referred to objects that appeared fuzzier than stars - although astronomers subsequently identified many of these as galaxies. What we now call nebulae are formed in several ways: from the remains of exploding stars, the remnants of smaller stars that simply fade away, or from a mass of interstellar gas that pulls itself together under its own gravity.

What we now call nebulae are formed in several ways: from the remains of exploding stars, the remnants of smaller stars that simply fade away, or from a mass of interstellar gas that pulls itself together under its own gravity.