Nebula tend to mark the beginnings and endings of the life of stars.
Glowing red emission nebula are often formed by the young stars lighting up the clouds
of hydrogen from which they formed. Other nebula may be formed by the titanic explosion
of a supernova or the more gentle expulsion of an old star's outer layers, each of them
marking the ending of a star. Blue nebula are formed by starlight reflecting off
neighboring clouds of gas and dust. Dark nebula are caused by such clouds blocking
the light behind them from our perspective. However they form, nebula are among the
most interesting and beautiful things in the universe.

The most recent images are on the top of this gallery.