A small section of the expanding remains of the Veil Nebula, a massive star that exploded about 8,000 years ago. The entire nebula is 110 light-years across, covering six full moons on the sky as seen from Earth, and resides about 2,100 light-years away in the constellation Cygnus, the Swan. Image taken by NASA's Hubble Space Telescope. Released September 24, 2015. (Photo by Reuters/NASA/ESA/Hubble Heritage Team)