NASA discovers new Neptune moon

Using archival images from NASA's Hubble Space Telescope, an astronomer discovered another small moon circling around Neptune. Mark Showalter, of the SETI Institute in California, plotted the movement of a white dot in more than 150 images taken by Hubble from 2004 to 2009.

"The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system," he said in a NASA press release. "It's the same reason a sports photographer tracks a running athlete -- the athlete stays in focus, but the background blurs."

This is the 14th moon of the distant planet, and the smallest yet. Named S/2004 N 1, it is estimated to measure about 12 miles across and is located 65,400 miles from Neptune, between fellow Neptunian moons Larissa and Proteus. It circles the blue-green planet every 23 hours.

Star gazers shouldn't expect to spot the moon -- it is 100 million times fainter than the faintest star we can see, according to NASA. Even a NASA spacecraft, Voyager 2, missed the moon when it flew past and surveyed the Neptunian system in 1989.