Moon No. 5 Found for Pluto

Just 6 miles across, P5 is Pluto's smallest moon yet

By Mark Russell, Newser Staff

Posted Jul 12, 2012 5:33 AM CDT

Copied

Moon No. 5 Found for Pluto — This image, taken by the NASA/ESA Hubble Space Telescope, shows five moons orbiting the distant, icy dwarf planet Pluto. The green circle marks the newly discovered moon, designated S/2012 (134340) 1, or P5. (Getty Images)

It's not a chapter in the Twilight series, but it is a new moon: astronomers have discovered a tiny fifth satellite revolving around distant Pluto, reports Space.com. One year after P4 was announced, now the Hubble Telescope has spied a fifth moon. Pluto's biggest moon, Charon, is 648 miles across and P4 is between 8 and 21 miles across, but the new moon is even smaller—perhaps as small as 6 miles across.

"The moons form a series of neatly nested orbits, a bit like Russian dolls," says the SETI team leader. The new moon's official name, at least for now, is S/2012 (134340) 1, but most people are just calling it P5. It is irregularly shaped and rotates around Pluto at a distance of 29,000 miles. Just don't get your hopes up that another moon might be enough to promote Pluto back to being a planet. "Does it change the planetary status? Of course not," says one CalTech astronomer. (Read more Pluto stories.)