A doomed star exploded some 20,000 years ago, its tattered remnants continue racing into space at breakneck speeds and NASA's Hubble Space Telescope has caught the action. The nebula, called the Cygnus Loop, has a width of six full Moons as seen on the sky. Astronomers used Hubble to zoom into a very small slice of the leading edge of this expanding supernova bubble, where the supernova blast wave plows into surrounding material in space. Hubble images taken demonstrate how the remnant's shock front has expanded over time, and they used the crisp images to clock its speed. It is a reminder that our actions will be expanded into the future for all generations to experience.