spacetoday.net: Fifth moon spotted orbiting Pluto

Posted: Thu, Jul 12, 2012, 5:40 AM ET (0940 GMT)
Pluto P5 moon in July 2012 (STScI)

Astronomers announced Wednesday the discovery of a fifth, and very small, moon orbiting the dwarf planet Pluto. Scientists detected the moon, temporarily designated S/2012 (134340) 1, in Hubble Space Telescope images of Pluto taken in late June and early July. The moon is thought to be irregular in shape and between 10 and 24 kilometers across, and in a circular orbit about 42,000 kilometers from Pluto. The moon is the fifth found orbiting Pluto and the second in as many years. Scientists said the searches for moons orbiting Pluto suggest that there are many more smaller particles orbiting the planet, information that will help plan a safe flyby for NASA's New Horizons spacecraft when it goes past Pluto in 2015. The discovery does not affect Pluto's designation as a "dwarf planet" assigned to it by the International Astronomical Union in 2006.