This close-up look at Saturn's moon Janus reveals spots on the moon's surface which may be dark material exposed by impacts. If the dark markings within bright terrain are indeed impact features, then Janus' surface represents a contrast with that of Saturn's moon Phoebe, where impacts have uncovered bright material beneath a darker overlying layer. Janus is 181 kilometres across and may be a porous body, composed mostly of water ice.
This image was taken in visible light with the Cassini spacecraft narrow-angle camera on 20 May 2005, at a distance of approximately 357 000 kilometres from Janus and at a Sun-Janus-spacecraft, or phase, angle of 6 degrees. Resolution in the original image was 2 kilometres per pixel. The view was magnified by a factor of two and contrast-enhanced to aid visibility of the moon's surface.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency.