SCIENCE IN THE NEWS DAILY
Pluto's Moons Offer Hints of Alien Worlds
from ScienceNOW Daily News
Planet or not, Pluto and its newest moons may tell us a lot about how other worlds orbit distant stars. A new computer simulation based on the motions of Pluto's satellites not only zeroes in on the masses of two of the moons but predicts that planets orbiting double stars are more widely spaced from one another than are the worlds of single stars such as the sun.
Once thought to be a lonely outpost at the solar system's edge, Pluto now has four known moons. The first, discovered in 1978 and named Charon, is half Pluto's size. The Hubble Space Telescope spotted two more, Nix and Hydra, in 2005, orbiting beyond Charon, then another in 2011. In mythology, Pluto was the god of the underworld, so the names of the satellites reflect the same dark theme: Charon ferried souls of the dead across the River Styx; Nix was the goddess of night; and Hydra was a nine-headed monster who lived in a lake near an underworld entrance.
Now astronomers Andrew Youdin, Kaitlin Kratter, and Scott Kenyon of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, have analyzed Pluto's newest moon, which does not yet have a permanent name. It's the smallest of the bunch and moves between the orbits of Nix and Hydra.