Meridiani Terra had liquid water
Mar. 2nd, 2004 06:10 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
mmcirvinAsa Dotzler has a blow-by-blow synopsis of today's JPL press conference. The gist of it: The Opportunity rover landed in a place that once had liquid water for a sustained period of time, though whether it was underwater (and the rocks sedimentary) or just had percolating groundwater is still unknown. NASA has always been very enthusiastic about the formerly-wet-Mars hypothesis, but this is by far the most solid evidence that there was sustained groundwater somewhere, and not just, say, flash floods that quickly froze or evaporated.
Lots of people on the Internet have been talking about things showing up in various microscopic-imager photos that look like they might be fossils of living things: the "rotini", the "shrimp", etc.; and some were hoping that this announcement would be The Big One: solid evidence of past life on Mars. I considered this unlikely. First, it's really easy to fool yourself when looking for interesting things in pictures of mystery objects, even if you are not Richard Hoagland or examining Piperi's belly. Second, since we have no idea what Martians might look like, there's no definite concept of what we're supposed to be looking for; things that look like Earth life might be completely wrong. Third, even on Earth, you don't find fossils everywhere, so even if there was Martian life it's no guarantee that Opportunity would find the remains (fossils of creatures without hard parts are particularly rare).
Fourth, and most importantly, the MER teams are surely intensely aware of the preceding facts, as well as the controversies surrounding past claims of extraterrestrial life; and everything they've said and done so far convinces me that they behave like professional scientists should. Even if there were clear and unambiguous imprints of hundred-legged beasties in the rock, they'd undoubtedly take longer to draw the obvious conclusion than they've had so far. The announcement of fossil life on Mars would be so big that anyone planning to make it would want first to submit the data to a level of scrutiny that most people would consider pathological. Something kind of funny-looking that might be interpretable as a Martian worm just wouldn't cut it.
Right now, I've got to believe that some of the MER people are pining for the absence of a more powerful microscope on the rover (the Microscopic Imager is intended more as the equivalent of a geologist's hand magnifier). The 2009 Mars Science Laboratory mission might do better.
Lots of people on the Internet have been talking about things showing up in various microscopic-imager photos that look like they might be fossils of living things: the "rotini", the "shrimp", etc.; and some were hoping that this announcement would be The Big One: solid evidence of past life on Mars. I considered this unlikely. First, it's really easy to fool yourself when looking for interesting things in pictures of mystery objects, even if you are not Richard Hoagland or examining Piperi's belly. Second, since we have no idea what Martians might look like, there's no definite concept of what we're supposed to be looking for; things that look like Earth life might be completely wrong. Third, even on Earth, you don't find fossils everywhere, so even if there was Martian life it's no guarantee that Opportunity would find the remains (fossils of creatures without hard parts are particularly rare).
Fourth, and most importantly, the MER teams are surely intensely aware of the preceding facts, as well as the controversies surrounding past claims of extraterrestrial life; and everything they've said and done so far convinces me that they behave like professional scientists should. Even if there were clear and unambiguous imprints of hundred-legged beasties in the rock, they'd undoubtedly take longer to draw the obvious conclusion than they've had so far. The announcement of fossil life on Mars would be so big that anyone planning to make it would want first to submit the data to a level of scrutiny that most people would consider pathological. Something kind of funny-looking that might be interpretable as a Martian worm just wouldn't cut it.
Right now, I've got to believe that some of the MER people are pining for the absence of a more powerful microscope on the rover (the Microscopic Imager is intended more as the equivalent of a geologist's hand magnifier). The 2009 Mars Science Laboratory mission might do better.
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Fossilized Pasta?
Date: 2004-03-02 04:56 pm (UTC)http://www.space.com/missionlaunches/mars_rocks_040226.html