If Mars Had Water, It Wasnt for Long
The Mars Exploration Rovers found evidence for the minerals jarosite and gypsum. Jarosite has been found on earth in connection with lava and acidic, sulfur-rich fluids, but usually only persists in an arid environment, says a press release from Virginia Tech based on a paper in Nature last week.1 Consequently, jarosite might be an indicator of a water-limited environment, and “liquid water may have been on Mars briefly.”
As to how much water was on Mars, the researchers do not know if there was a great deal for a short time or a little for a longer period. However, they can say there was a geologically short window in which liquid water was present, suggesting there also was a limited time period when conditions may have been hospitable for life, [Donald] Rimstidt said.
1Madden, Bodnar and Rimstidt, “Jarosite as an indicator of water-limited chemical weathering on Mars,” Nature 431, 821 – 823 (14 October 2004); doi:10.1038/nature02971.
The wet-Marsers are losing, and the Mars-lifers are down for the count. The place reeks with sulfur and is bombarded by death rays. The solar wind is dehydrating the whole planet. Sorry, Percival.