Hubble Caldwell 27, Crescent Nebula

Commonly called the Crescent Nebula, Caldwell 27 looks more like a prehistoric dinosaur egg. Hubble’s vibrantly colored image zooms in on a small region of the nebula that is “only” 3 light-years across, or about 17.6 trillion miles. This close-up of the nebula reveals with unprecedented clarity that the shell of matter is a network of filaments and dense knots, all enshrouded in a thin “skin” of gas (seen in blue).