... A Piece of Interplanetary Dust . ... A Mystery in Gamma Rays . ... Tycho and Copernicus: Lunar Ray Craters . ... Dazzling in binoculars or a small telescope, the Moon is pocked with impact craters. ... Farewell Jupiter . ... The Cassini spacecraft, launched from Earth four years ago, has now swung past Jupiter and should arrive at Saturn in the year 2004. Pictured to the left is a parting shot from Cassini in January that would not have been possible from Earth: Jupiter showing a crescent phase. ...