Published online 10 December 2008 | Nature 456, 690-695 (2008) | doi:10.1038/456690a
Corrected online: 23 December 2008
Box: Strange brew
From the article:
Mars exploration: Phoenix: a race against time.
Eric Hand
Sol 8: Specks on the lander's legs could turn out to be briny water.NASA/JPL-CALTECH/UNIV. ARIZONA/MAX PLANCK INST.
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Early in the mission, Renno suggested that little specks on the lander's legs were splashes of salty mud kicked up by its retro-rockets during the landing. However, when the camera returned to check on the legs weeks later, the images suggested something extraordinary: the specks might be growing.
Renno now says that the specks — which he claims are not only growing but also merging and moving — had become briny water droplets. The lander legs, he says, are about 20 ºC warmer than the surface because of the spacecraft's heaters. This, combined with the effects of perchlorate, allowed droplets to form. If liquid water exists on the lander leg in just a few randomly spattered spots, he speculates, what about in the soil itself? On Earth, small layers of briny water exist within massive chunks of sea ice. Why couldn't the same be true in the boundaries between ice and soil on Mars where salts might be expected to accumulate? "I'm not saying that there's liquid water everywhere on Mars. I'm just saying that these results suggest that it is possible," says Renno.
The idea has been hotly debated within the team. Renno says he will submit a paper to the Journal of Geophysical Research that describes the droplets and asserts that briny water is "common". He says he has two dozen co-authors from the science team. But there are some notable absences on the list, including Hecht and Ray Arvidson, a senior mission scientist from Washington University in St Louis. "My impression is that Nilton is running with the most spectacular hypotheses," says Arvidson.
http://www.nature.com/news/2008/081210/full/456690a/box/1.html
Bob Clark
Space/Science » in reply to Some 40th LPSC Phoenix abstracts.
More on those white blobs on the landers legs.