Deep-Space Photos: Hubble's Greatest Hits

More Than a Caterpillar
A cosmic butterfly hovers in a lightly populated region of the Milky Way, 2,000 light years from Earth. Known as Sharpless 2-106, it gets its roughly symmetrical shape from outrushing heat streaming into a cold environment.

• A Brief History of the Hubble Space Telescope
• Eathrise: Iconic Images of Earth from Space