By Maria Panagiotidi
A fifth moon was discovered orbiting Pluto by a team of astronomers using NASA’s Hubble space Telescope.
The icy dwarf planet Pluto has four other known moons, the largest being Charon which was discovered in 1978 at the United States Naval Observatory in Washington, D.C. Hubble observations in 2006 uncovered two additional small moons, Nix and Hydra. Pluto’s fourth moon, which is provisionally named “P4″, was discovered almost a year ago.
This image, taken by NASA's Hubble Space Telescope, shows five moons orbiting the distant, icy dwarf planet Pluto. The green circle marks the newly discovered moon, designated P5, as photographed by Hubble's Wide Field Camera 3 on July 7. (Source: Hubblesite.org)
Pluto’s fifth moon was provisionally named P5 and was detected in nine separate sets of images taken by Hubble’s Wide Field Camera 3 on 26, 27 and 29 June, and 7 and 9 July 2012. It is estimated to be irregular in shape and 6 to 15 miles across. P5 is in a 58,000-mile-diameter circular orbit around Pluto that is assumed to lie in the same plane as Pluto’s other known moons.
Scientists are intrigued that such a small planet (Pluto is smaller than our moon) can have such a complex collection of satellites.
“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 in Laurel, Md.
The new discovery provides additional clues about the formation and evolution of the Pluto system. The most popular theory suggests that all the moons are relics of a collision between Pluto and another large Kuiper belt object billions of years ago. The Kuiper belt refers to a region of the Solar System that consists mainly of small icy bodies.
The new detection will allow scientists navigate NASA’s New Horizons spacecraft through the Pluto system in 2015, when it is expected to make an historic and long-awaited high-speed flyby of the distant world. New Horizons will return the first ever detailed images of the Pluto system.
Official NASA announcement here: http://www.nasa.gov/mission_pages/hubble/science/new-pluto-moon.html
