Tuesday, March 03, 2009

Drip drip of evidence builds for water

The jury is likely to be out for some time, but intriguing images have come to light that seem to show drops of water that had formed on the landing strut of the Phoenix Mars lander. The "drops" are seen over a period of days to form, drip and merge down the struts. Study leader and Phoenix co-investigator Nilton Renno of the University of Michigan believes that the drops may have started life as saline mud that was splashed up onto the struts during the landing of the Phoenix probe. Salt in the mud would then have absorbed water vapour from the atmosphere to form the watery drops. The "water" might contain a substance called perchlorates, which acts as a powerful antifreeze, so though the drops may have partially frozen at night, they would have been in a liquid state during daylight hours. However, caution is urged, as it would not be likely that this highly salty water would be a good place for life to form.