Light Echo - February 8, 2004
The light from a distant sun can take thousands of years to reach Earth. Looking at the night sky is like watching ghosts—some of the stars may have burnt out long ago. In 2004, Hubble captured a light burst from the star V838 Monocerotis, a red supergiant on the outer edge of our Milky Way. The light pulse, which illuminates the dust clouds surrounding the star, took place 20,000 years ago.