6 July: Scientists pore over images of Saturn's rings, snapped as Cassini flew right through the middle of them during its orbit insertion on 1 July. This image captured ultraviolet light reflected by the rings, and highlights just how dirty they are. The 'dirt' - a mixture of mineral grains and organic molecules - shows up as red, while water ice appears blue. The thick red band in the outer part of the rings is the Encke gap, a 300-kilometre-wide division in the A ring opened up by the gravitational effects of the moonlet Pan.