Saturn's rings: cold and colder

This image of Saturn's rings was made from data taken by the composite infrared spectrometer instrument on board Cassini-Huygens.

Red represents temperatures of about -163 degrees Celsius, green is about -183 degrees Celsius and blue -203 degrees Celsius. Water freezes at zero degrees Celsius.

The spatial resolution of the ring portion of the image is 200 kilometres. The temperature measurements were made on 1 July 2004, on the unlit side of the rings.

In order to show the full breadth of the rings, a strip of temperature data was mapped onto a picture of the lit side of the rings taken with the Cassini-Huygens narrow-angle camera on 11 May 2004, a little over a month before Saturn orbit insertion.

Cassini-Huygens is too close to the planet and hence no pictures of the unlit side of the rings are available, so the temperature data were mapped onto a picture of the lit side of rings.

Saturn is overexposed and pure white in this picture. Saturn's moon Enceladus is visible below the rings, toward the centre.