Planetary Nebula PK40-0.1

Planetary Nebula PK40-0.1 |  In theory all Planetary Nebula should look like this one: a nearly perfect sphere with a brightened limb. The reality is that most nebulae are found in a wide variety of shapes and colors. Round ones like PK 40-0.1 are actually a rarity in the Universe.

Image Credit: John Pierce/Adam Block/NOAO/AURA/NSF