Press Release: VIMS Finds No Ammonia on Enceladus

JPL has posted an image advisory regarding today's Titan and Enceladus images. While there really isn't that much new in the release that isn't in the figure captions, what is puzzling is the description of the VIMS Enceladus data by Roger Clark:

Other preliminary results from the visual and infrared mapping spectrometer show a surface composed of only pure water ice, with no other compounds detected. Ammonia or ammonium compounds and carbon dioxide were expected, but not seen in the data. Further analysis may find trace amounts. "The spectra look like laboratory fabricated water ice, indicating the ice is quite pure," said Dr. Roger N. Clark, Cassini science team member at the U.S. Geological Survey in Denver.

Thos definitely puts a monkey wrench into theories on Enceladean geology.