February 3, 2000: When 19th century astronomer Sir John Herschel spied a swirling cloud of gas with a hole punched through it, he dubbed it the Keyhole Nebula. Now the Hubble telescope has taken a peek at this region, and the resulting image reveals previously unseen details of the Keyhole's mysterious, complex structure. The Keyhole is part of a larger region called the Carina Nebula (NGC 3372), about 8,000 light-years from Earth.
The keyhole is the circular feature that dominates the picture and is about 7 light-years wide. The round structure contains bright filaments of hot, glowing gas and dark silhouetted clouds of cold molecules and dust, all of which are in rapid, chaotic motion. Hubble's clear view also shows several small, dark globules that may be in the process of collapsing to form new stars. This region is a rich breeding ground for some of the hottest and most massive stars known, each about 10 times as hot and 100 times as hefty as the Sun. The famous explosive variable star Eta Carinae also lies just outside the upper right of the picture.