Not all of the material in our universe is contained in stars. A large amount of interstellar matter exists in the form of cloud-like objects called nebulae. A nebula is made up of very tenuous gas and dust. Gaseous nebulae are of such great importance because it seems that it is here that stars are born. It is here that fresh stars are condensing out of the nebular material. The three main types of nebulae are illustrated above. In most of space, these interstellar dust clouds are cold and dark. Dark clouds block our view to the very center of our Galaxy. Were it not for these obscuring dark nebulae, the nuclear region of the galaxy would be a blaze of light filling the night sky in that direction.

There are two types of nebulae that 'shine': emission nebulae and reflection or continuum nebulae.

Copyright (c) 1997-99 Michael Erlewine