Friday, March 21, 2008

Friday beautiful science

Okay, I've been doing a lot of astronomy photos for my Friday's, but it's only because those damn astronomers have been pumping out all kinds of great photos. This photo comes from the Cassini probe. From the Jet Propulsion Lab:

Cassini's March 2008 flyby of Enceladus was designed to directly investigate the ongoing plume activity at the moon's south pole, but the path of the spacecraft allowed investigation of older evidence for internal activity near the north pole.

Compared to much of the moon's southern hemisphere—the south polar region in particular—the north polar region is much older and covered with craters. These craters are captured at different stages of disruption and alteration by tectonic activity and probably past heating from below. Many of the craters seen here are sliced by small parallel cracks that seem to be ubiquitous throughout the old cratered terrains on Enceladus. The mosaic also shows a variety of impact crater shapes, some with bowed-up floors and smaller craters within, very likely indicating that the icy crust in this area was at some time warmer than at present. While this conclusion was previously reached from NASA Voyager spacecraft images, these new data provide a much more detailed look at the fractures that modify the surface. This data will give a significantly improved comparison of the geologic history at the satellite's north pole with that at the south pole.
Hat tip to Emily.


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