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Should be so common, right? Yet we're struggling to find any form of life. Not complex, just anything that lives.

by mavili 3y ago

simiones 3y ago
I don't think we have any tools that could possibly detect bacterial life anywhere where we don't have a physical presence at the moment. That is, even if Venus were teeming with simple life on every square cm, I don't think any of our instruments could pick it up unless we send a probe to collect and analyze samples. So, at the moment we have no hope of detecting this type of life outside the solar system even if it were universal.
- jodrellblank 3y ago
  We've got photos from the surface of Venus: https://www.planetary.org/articles/every-picture-from-venus-surface-ever https://www.planetary.org/articles/every-picture-from-venus-... It's visibly not covered in moss, fungus, grasses, algae, slime. On Earth we talk about hot hydrothermal vents underwater: https://www.nhm.ac.uk/discover/survival-at-hydrothermal-vents.html https://www.nhm.ac.uk/discover/survival-at-hydrothermal-vent... - this says "the Pompeii worm [...] is one of the most heat-resistant multicellular animals on the planet, able to withstand temperature spikes of over 80°C. 'Most animals can't cope with anything over 40°C. Very close to the hot fluid, there are typically only microorganisms. These can survive in temperatures up to around 120°C,' explains Maggie." The surface of Venus averages 462°C. Okay we won't know for sure unless we collect samples, but we do know any life would have to be heat resistant beyond anything we know of - beyond what our metal space probes could tolerate - and invisible to the naked camera even in 'teeming' quantities, and leaving no trace of waste gasses in the atmosphere which we can detect remotely. [ https://www.youtube.com/watch?v=nvkMwv9EYQQ https://www.youtube.com/watch?v=nvkMwv9EYQQ - Venera: The Incredible Probe that the Soviets Sent to Venus ]
  - deleted 3y ago
    [deleted]
  - nojs 3y ago
    Venus is perhaps a bad example but the point is true for all the other more likely places (Europa and others with subsurface oceans). We just haven’t explored them enough yet.
  - simiones 3y ago
    Agreed - Venus is particularly unlikely to have any life because of its temperatures, I wasn't trying to claim otherwise, just choosing a near neighbor for which we haven't ever tried to look at its rocks through a microscope. However, those pictures don't tell us anything about the presence of microscopic life. On Earth at least, only a quite tiny subset of unicellular life-forms leave any trace large enough to be visible at that level of magnification. Even if they are there in quite large quantities. "Teeming" is of course a relative term, but imagine that there were 1000 unicellular organisms similar to an amoeba on every square cm of those pictures. Would you expect to see anything?
    - jodrellblank 3y ago
      Given that I don’t see anything on toilets or kitchen worktops even knowing bacteria is there, no I wouldn’t expect to. But I also wouldn’t expect to at 460C, and would rather see core samples from Mars’s ice caps
saalweachter 3y ago
Humans, living on one planet: "Life is everywhere!" Humans, after soft landing probes on two other planets: "Life is nowhere out there! It must be only here!"

Should be so common, right? Yet we're struggling to find any form of life. Not complex, just anything that lives.

by mavili 3y ago

Should be so common, right? Yet we're struggling to find any form of life. Not complex, just anything that lives.

I don't think we have any tools that could possibly detect bacterial life anywhere where we don't have a physical presence at the moment. That is, even if Venus were teeming with simple life on every square cm, I don't think any of our instruments could pick it up unless we send a probe to collect and analyze samples. So, at the moment we have no hope of detecting this type of life outside the solar system even if it were universal.

jodrellblank 3y ago
We've got photos from the surface of Venus: https://www.planetary.org/articles/every-picture-from-venus-surface-ever https://www.planetary.org/articles/every-picture-from-venus-... It's visibly not covered in moss, fungus, grasses, algae, slime. On Earth we talk about hot hydrothermal vents underwater: https://www.nhm.ac.uk/discover/survival-at-hydrothermal-vents.html https://www.nhm.ac.uk/discover/survival-at-hydrothermal-vent... - this says "the Pompeii worm [...] is one of the most heat-resistant multicellular animals on the planet, able to withstand temperature spikes of over 80°C. 'Most animals can't cope with anything over 40°C. Very close to the hot fluid, there are typically only microorganisms. These can survive in temperatures up to around 120°C,' explains Maggie." The surface of Venus averages 462°C. Okay we won't know for sure unless we collect samples, but we do know any life would have to be heat resistant beyond anything we know of - beyond what our metal space probes could tolerate - and invisible to the naked camera even in 'teeming' quantities, and leaving no trace of waste gasses in the atmosphere which we can detect remotely. [ https://www.youtube.com/watch?v=nvkMwv9EYQQ https://www.youtube.com/watch?v=nvkMwv9EYQQ - Venera: The Incredible Probe that the Soviets Sent to Venus ]
- deleted 3y ago
  [deleted]
- nojs 3y ago
  Venus is perhaps a bad example but the point is true for all the other more likely places (Europa and others with subsurface oceans). We just haven’t explored them enough yet.
- simiones 3y ago
  Agreed - Venus is particularly unlikely to have any life because of its temperatures, I wasn't trying to claim otherwise, just choosing a near neighbor for which we haven't ever tried to look at its rocks through a microscope. However, those pictures don't tell us anything about the presence of microscopic life. On Earth at least, only a quite tiny subset of unicellular life-forms leave any trace large enough to be visible at that level of magnification. Even if they are there in quite large quantities. "Teeming" is of course a relative term, but imagine that there were 1000 unicellular organisms similar to an amoeba on every square cm of those pictures. Would you expect to see anything?
  - jodrellblank 3y ago
    Given that I don’t see anything on toilets or kitchen worktops even knowing bacteria is there, no I wouldn’t expect to. But I also wouldn’t expect to at 460C, and would rather see core samples from Mars’s ice caps

saalweachter 3y ago

Humans, living on one planet: "Life is everywhere!" Humans, after soft landing probes on two other planets: "Life is nowhere out there! It must be only here!"