The temperature of Saturn's rings
The varying temperatures of Saturn's rings are depicted here in this false-colour image from the NASA/ESA/ASI Cassini-Huygens spacecraft.
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 image shows that the opaque region of the rings, like the outer A ring (far right) and the middle B ring, are cooler, while more transparent sections, like the Cassini Division (in red just inside the A ring) or the inner C ring (shown in yellow and red), are relatively warmer.
The temperature measurements were made on 1 July 2004, on the unlit side of the rings. Cassini 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.
The Cassini-Huygens mission is a co-operative project of NASA, ESA and ASI, the Italian space agency.