NASA's Galaxy Evolution Explorer grabbed this ultraviolet image of the wispy gas clouds of the Cygnus Loop, a remnant of a supernova that occurred 5,000 to 8,000 years ago. The remnant is about 1,500 light years away from Earth. It is in the direction of the constellation Cygnus and, if visible to the naked eye, it would take up as much space in the sky as three full moons.

Below, recent Pictures of the Day:

Image: NASA.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.