Fifth moon discovery reminds us how little we know about Pluto (+video)
Orbiting at outskirts of the solar system some three billion miles from Earth, Pluto remains shrouded in mystery.
A fifth moon orbiting the dwarf planet Pluto has turned up in new Hubble Space Telescope images. Planetary scientists say the newfound moon serves as yet another reminder of how little we really know about this remote, chaotic world.
"Every time we look harder, we find new stuff," said Alan Stern, a planetary scientist at the Southwest Research Institute in Boulder, Colo., and a member of the moon's discovery team. In recent decades, he and his colleagues have identified signs of an atmosphere on the dwarf planet, as well as polar caps, a high albedo (highly reflective surface), and of course, a growing collection of moons.
But in-depth investigation of Pluto has proven tremendously difficult from 3 billion miles away. The best images we have of the icy world come from the Hubble Telescope, but to the untrained eye, they're not much to behold. At a slim 1,429 miles wide — roughly the distance from Maine to the tip of Florida — Pluto will likely remain a dim blur until NASA's New Horizons spacecraft arrives there in July 2015.