Is this coating evidence of microbial activity?



Episode 72
Thin dark coatings known as desert varnish are common on rocks in arid regions on Earth and they’re thought to form in part from microbial activity. Now, on Mars, the Perseverance rover has found similar coatings.

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45 thoughts on “Is this coating evidence of microbial activity?”

  1. Looks fascinating but I'm still rather skeptical regarding life on Mars ever being a thing. These layers have to be fairly recent, forming long after the lake dried out and bottom got eroded since it sits on already eroded sides of these rocks. My guess is, it's another form of those metallic beads rovers met in other places which also looked fascinating but I believe were already proven to be of anorganic origin. But we'll see, I am pretty sure Nasa will do their best to figure out what it is.

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  2. Amazing video and pictures once again… Is that a waterfall (sand as water) cascading over the fractures i the rock ? Do you guys know how the large pieces of the stratified rock break so cleanly into 'bricks' in places ..

    Again if we were betting the form is showing the odds of life being found shortening ! 🤟🏻

    Nice work Again

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  3. it sure looks like desert varnish, surely the laser shots will give some good indication or minerals present to say yes or no towards life? this is huge!

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  4. I have often wondered why they don't fly even modest optical microscopes on these missions. Enough that you'd have a decent chance of spotting a microbe fossil.
    Part of me feels like that might be too definitive in the negative direction if nothing were found and they would lose funding based on the hope of finding life.

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  5. Wow. I sincerely hope we can get a sample back to earth. Like some of the other commenters have already mentioned, thank you for your measured tones regarding possible evidence of microbial life. Still exciting though!

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  6. Neat. If it is indeed a coating then it would imply a hiatus in aeolian erosion. Active ventifacts on Earth don't collect coatings or lichen, etc, because sand abrasion keeps them cleaned of it.

    I'm curious about whether this dark surface is preferentially found on the downwind side (~west-facing side) of the rocks. If there was an erosional hiatus, could this surface/'coating' have been more widespread, and now is only present on surfaces protected from abrasion?

    There's been so much backwasting of these delta deposits that any existing coatings would probably be relatively recent. Still, they're very cool.

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  7. Rock-/desert varnish kind of coatings and other putative micro-biology related structures were spotted by EVERY rover mission on Mars so far. Even in the Viking imagery there was hints of such. A very interesting topic for sure. If this turns out to be related to microbes – Mars seems full of microbial life (maybe dirstributed by the dust storms) literaly hidden in plain sight. Mr Levin s labeled release experiment results may have shown us the truth about life on Mars all the time since Viking 😉
    So not realy new news but exciting none the less.

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  8. "Mars Guy" provides a well respected channel for all Mars enthusiasts. Updating (mostly) Perseverance and Ingenuity releases using reason, size/ distance comparisons and imagination. Mars as viewed through the eyes of a geologist. I appreciate the professionalism and effort involved, I never miss a new release!

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