NASA has confirmed the discovery of a fifth moon orbiting the icy dwarf planet Pluto.
Astronomers believe the moon is somewhat irregular in shape, measuring approximately 6-15 miles across. It is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to be co-planar with the other satellites in the system.
"The moons form a series of neatly nested orbits, a bit like Russian dolls," explained team lead Mark Showalter of the SETI Institute in Mountain View, California.
According to Showalter, the Pluto team is quite intrigued that such a small planet boasts a complex collection of satellites.
"The new discovery provides additional clues for unraveling how the Pluto system formed and evolved," he sai. "The favored theory is that all the moons are relics of a collision between Pluto and another large Kuiper belt object billions of years ago."
Discovery of the new moon is expected to help scientists navigate NASA's New Horizons spacecraft through the Pluto system in 2015, when it conducts a high-speed flyby of the distant world.
In the meantime, NASA is currently scouring the Pluto system with Hubble to uncover potential hazards to the New Horizons spacecraft. Moving past the dwarf planet at a speed of 30,000 miles per hour, New Horizons could be destroyed in a collision with even a BB-shot-size piece of orbital debris.
Pluto's largest moon, Charon, was discovered in 1978 in observations made at the United States Naval Observatory in Washington, D.C. In 2006, astronomers poring over Hubble data confirmed the existence of two additional small moons, Nix and Hydra, while P4 was identified in 2011.