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The "dry Mars" hypothesis has been dead for decades. At this point we have about as much evidence for water on Mars as we have for water on Earth. The media is
by planetguy 14y ago
The "dry Mars" hypothesis has been dead for decades. At this point we have about as much evidence for water on Mars as we have for water on Earth.
The media is always keen on every new "omg, there was once water on Mars" discovery, but we've moved on to trying to figure out the details; where, when, how much, where did it go?
- jakeonthemove 14y agoI thought we figured that out - it disappeared (vaporized) as the planet got closer to the sun and slowed down in spinning... That said, I'm impressed at Opportunity - this rover is just as sturdy as the Voyagers - I hope Curiosity is just as well built and lands safely...
- planetguy 14y agoMars had water far more recently than it had any substantially different orbit. The sun has been getting brighter over the past four billion years, too, but afaik that isn't enough to stick together a full Martian climate history. There's other stuff going on which we don't fully understand yet. Opportunity is far more impressive than Voyager. Voyager has basically been sitting in a nice clean vacuum doing nothing for the past thirty-five years, it's no wonder it's still working. Opportunity has been hard-scrabbling around in sandy, dusty environments, heating up in the day and cooling down at night, with dozens of joints and moving parts waving around all day.
- phaedrus 14y agoI was under the impression the accepted reason for Mars losing water was it being carried off by solar wind due to Mars' lack of a strong magnetic field, that lack in turn being caused by its smaller size making its outer core not remaining molten like Earth's to generate a dynamo current.
- InclinedPlane 14y agoMars continues to have large amounts of water ice in the form of sub-surface permafrost across most of the planet.
- MartinCron 14y agoAt this point we have about as much evidence for water on Mars as we have for water on Earth Be careful with language like that. Sloppy journalists might turn that into a "we need to balance both sides of the story" and we'll wind up with people denying the existence of water on Earth.
- planetguy 14y agoHey, I'm cool with solipsism.
- InclinedPlane 14y agohttp://www.smbc-comics.com/index.php?db=comics&id=2376#comic http://www.smbc-comics.com/index.php?db=comics&id=2376#c...