Release 910 of 1,057
Hubble's Close-Up View of a Shock Wave from a Stellar Explosion
Release date: Feb 20, 1995 12:00 AM (EST)

This Hubble telescope image shows a small portion of a nebula called the "Cygnus Loop." This nebula is an expanding blast wave from a stellar cataclysm, a supernova explosion, which occurred about 15,000 years ago.

The supernova blast wave, which is moving from left to right across the picture, has recently hit a cloud of denser-than-average interstellar gas. This collision drives shock waves into the cloud that heats interstellar gas, causing it to glow.