Astro News Briefs: August 16–22

Two New Moons for Saturn

August 18, 2004 | Saturn's family just got a little bigger. While examining Cassini images on his laptop computer during vacation, Sebastien Charnoz (University of Paris) discovered two small Saturnian moons, raising the ringed planet's tally to 33. The moons, temporarily designated S/2004 S 1 and S/2004 S 2, are only 3 and 4 kilometers (2 and 2.5 miles) across, respectively — much smaller than the previously smallest known Saturn satellites, which have a diameter of about 20 km. The diminutive moons follow circular paths around the ringed planet with periods of 1.01 and 1.14 days, putting them between the orbits of the major satellites Mimas and Enceladus. Considering that Cassini has just started its planned four-year orbital tour, expect more moon discoveries to follow.

A complete table of planetary moons can be found on our Guide to Planetary Satellites.