A fifth moon orbiting around the icy dwarf planet Pluto has been discovered by NASA's Hubble Space Telescope.
The moon, which is now provisionally known as S/2012 (134340) 1 or P5, has been detected in nine separate sets of images taken by Hubble's Wide Field Camera 3 on June 26, 27 and 29, and July 7 and 9.
P5, according to NASA, is irregular in shape and 6 to 15 miles across and is in a 58,000-mile-diameter circular orbit around Pluto.
Hubble's new finding will help scientists to explain how Pluto and its moons formed and evolved.
According to theory, Pluto's all moons are the debris created by the collision between Pluto and another large icy object billions of years ago.
"The moons form a series of neatly nested orbits, a bit like Russian dolls," said team leader Mark Showalter of Seti Institute in Mountain View.
"This is a very tidy system, and what that means is, it's an orbitally evolved system," Showalter said. "Literally there are shells where the orbits are stable."
Pluto's other four moons are Charon, Nix, Hydra and P4, all, apart from P4, are named after Greek mythological characters traditionally associate with the underworld. Charon, which was discovered in 1978 by the United States Naval Observatory station in Flagstaff, Arizona, is Pluto's largest moon. Nix and Hydra were discovered in 2006 and P4 is in 2011 by Hubble.
Hubble currently sees only the largest features of Pluto's surface and provides only a distant glimpse of the planet and its moons. But NASA's New Horizons space probe is currently en route to Pluto and should arrive on the planet surface in 2015. Moving at a speed of 30,000 miles per hour, NASA's spacecraft can be destroyed in a collision even with BB-pellet-size debris, the space research institute says. On its arrival, New Horizon will be NASA's first historic and long-awaited high-speed flyby of the distant world, capturing the detailed images of the dwarf planet.
The discovery of the new moon will help New Horizon team to avoid potential hazards and plan for a safer trajectory of the spacecraft, scientists believe.
"The discovery of so many small moons indirectly tells us that there must be lots of small particles lurking unseen in the Pluto system," said Harold Weaver of the Johns Hopkins University Applied Physics Laboratory.
Hubble, meanwhile, will soon be replaced by NASA's James Webb Space Telescope which will help researchers measure the surface chemistry of Pluto, its satellites along with other Kuiper belt objects.
