Time to open the tenth door in the advent calendar. Until the New Year, I'll be opening a door onto a different landscape from somewhere in the solar system. Where in the solar system is this jumble of bouldery fissures?
Just after its near-south-polar flyby of Enceladus on November 21, 2009, Cassini snapped several photos along Baghdad Sulcus, one of the four main "tiger stripes" that cross Enceladus' south pole. The main fissure of Baghdad crosses the image from the upper left corner to the lower middle. The Sun is coming from the upper left; some of the otherwise shadowed interiors of the fissures are lit by light reflected first off the Sun-facing fissure walls. The seamed surface is covered with a knobbly texture; here and there, I see what look like fans of material cascading down from steep fissure walls. But I think my favorite feature in this image is something I hadn't noticed before, a set of tiny little skinny parallel fractures running transverse to the tip of Baghdad Sulcus near the bottom center of the image. Those tiny things speak of the complicated pattern of tensional stresses concentrated at the tip of the crack. What an amazing landscape Cassini has revealed to us at Enceladus!
The Planetary Society Blog 2010 Advent Calendar