Blast into 2026: Conquer the Astronomy Challenge – Your Cosmic Adventure Awaits!

A nebula is indeed defined as a cloud of gas and dust, which plays a crucial role in the processes of star birth and death. These vast regions of space can serve as stellar nurseries, where gravity causes the gas and dust to condense, eventually leading to the formation of new stars. Alternatively, a nebula can also be the remnant material left over after a star has exploded in a supernova, spreading elements into the surrounding space.

This definition captures the essence of the various types of nebulae, including emission nebulae, which are vibrant with new star formation, and planetary nebulae, which are related to the end stages of a star's life cycle. Understanding nebulae is fundamental in astronomy, as they are key to the lifecycle of stars and the chemical enrichment of the galaxy.