spacetoday.net: Astronomers discover new moons around planet, asteroid

Posted: Sat, Oct 5, 2002, 8:16 AM ET (1216 GMT)
Two groups of astronomers announced this week the discoveries of new moons around the planet Uranus and a main belt asteroid. On Monday astronomers reported the discovery of S/2001 U1, a small moon orbiting Uranus. The object is no more than 20 kilometers in diameter and has an inclined, eccentric orbit around the planet. The moon is the 21st confirmed moon discovery for the planet. Matt Holman, the Harvard-Smithsonian Center for Astrophysics astronomer who led the discovery team, said that they have several other candidate moon discoveries, but poor observing conditions prevented his group from making the follow-up observations needed to confirm their existence. On the same day that the Uranian moon was discovered, another group reported the discovery of a moon around the asteroid 121 Hermione. The object, spotted by the Keck 2 telescope, is estimated to be about 13 km across; Hermione is 209 km across. Limited observations prevented astronomers from determining the orbit of the moon.