Perseverance's New Rock Samples Reveal Water Was Present on Mars For a Long Time (nasa.gov) 17
NASA's Mars rover Perseverance collected its second rock sample this week — and Friday Caltech's Ken Farley, a project scientist for the mission, announced that they've learned something.
"It's a big deal that the water was there a long time." The Perseverance science team already knew a lake once filled the crater; for how long has been more uncertain. The scientists couldn't dismiss the possibility that Jezero's lake was a "flash in the pan": floodwaters could have rapidly filled the impact crater and dried up in the space of 50 years, for example. But the level of alteration that scientists see in the rock that provided the core samples — as well as in the rock the team targeted on their first sample-acquisition attempt — suggests that groundwater was present for a long time.
This groundwater could have been related to the lake that was once in Jezero, or it could have traveled through the rocks long after the lake had dried up. Though scientists still can't say whether any of the water that altered these rocks was present for tens of thousands or for millions of years, they feel more certain that it was there for long enough to make the area more welcoming to microscopic life in the past.
And they discovered something interesting in the rock samples: salts. These salts may have formed when groundwater flowed through and altered the original minerals in the rock, or more likely when liquid water evaporated, leaving the salts. The salt minerals in these first two rock cores may also have trapped tiny bubbles of ancient Martian water. If present, they could serve as microscopic time capsules, offering clues about the ancient climate and habitability of Mars.
Salt minerals are also well-known on Earth for their ability to preserve signs of ancient life.
"It's a big deal that the water was there a long time." The Perseverance science team already knew a lake once filled the crater; for how long has been more uncertain. The scientists couldn't dismiss the possibility that Jezero's lake was a "flash in the pan": floodwaters could have rapidly filled the impact crater and dried up in the space of 50 years, for example. But the level of alteration that scientists see in the rock that provided the core samples — as well as in the rock the team targeted on their first sample-acquisition attempt — suggests that groundwater was present for a long time.
This groundwater could have been related to the lake that was once in Jezero, or it could have traveled through the rocks long after the lake had dried up. Though scientists still can't say whether any of the water that altered these rocks was present for tens of thousands or for millions of years, they feel more certain that it was there for long enough to make the area more welcoming to microscopic life in the past.
And they discovered something interesting in the rock samples: salts. These salts may have formed when groundwater flowed through and altered the original minerals in the rock, or more likely when liquid water evaporated, leaving the salts. The salt minerals in these first two rock cores may also have trapped tiny bubbles of ancient Martian water. If present, they could serve as microscopic time capsules, offering clues about the ancient climate and habitability of Mars.
Salt minerals are also well-known on Earth for their ability to preserve signs of ancient life.
Elon will tell us for sure (Score:1)
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I'm still waiting for my Full Self Driving autopilot to be fully enabled. Can we get that working first?
It works fine on the Falcon 9, what more do you want?
Ya, but has it been tested when an ISS crew member was on EVA changing a tire [axios.com] on the ISS?
We may be Martians (Score:2)
It's not unreasonable that Earth life formed on Mars. Mars was a more hospitable place earlier in the solar system's history. Earth was volcanic, stormy, and toxic earlier. And we already know that meteor strikes can launch rocks from Mars to Earth.
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I've never heard that theory, but it wouldn't change the premise much.
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There is a theory that the proto-Earth was hit by something about the size of Mars early in the development of the Solar system (some people even give it a name, "Theia", but so what?) ; but that is a very long way from saying that the two were a gravitationally bound double-planet binary.
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500 to maybe 800 million years before Earth started to develop things like free oxygen
According to some theories, "The Earth" itself never developed free oxygen. O2 was possibly a toxic byproduct from organisms that ingested methane and other gases and excreted oxygen. So by this approach, Mars-originating organisms could still have populated the early Earth.
Also, any organism hearty enough to have survived the journey from Mars to Earth could have done so regardless of the travel time; the organism(s) may have travelled through interplanetary space for thousands of years or hundreds of mill
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Some people struggle with that concept, but I don't. Why I object to wasting effort on panspermia - particularly the wilder fringes where organisms are flying between galactic arms or entire galaxies - is that it removes one of the few things that we do know : that one of the places that life can originate is the early Earth. Not that we have a terribly precise idea what those conditions were - little things like redox status
Dark side of Mars? (Score:2)
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But that's why we targeted this crater (Score:2)
In coming news : copper discovered by mining company after 15 year research and investigation programme into an area thought likely to contain significant amounts of copper.