I agree.We have the benefit of knowing extremeophiles exist on Earth as well as their biochemical activity.
The only way we will prove their existence on Venus is through direct detection.
Despite the process of elimination of non biochemical processes as being potential sources of phosphine on Venus, there remains the possibility of some unknown mechanism.
One can draw parallels with the mysterious element Nebulium.
Helium was discovered as a spectral line in the Sun's chromosphere before its discovery on Earth which was a success for remote observation.
Remote observations however can also lead to wrong conclusions.
The OIII spectral line in emission nebulae was wrongly attributed to an unknown element named Nebulium in the 19th century.
Nebulium turned out to be being a quantum mechanical "forbidden" transition of the doubly ionized oxygen atom O²⁺ which can only exist in the extreme vacuum of outer space due to low collision rates between atoms.
Basalt is just a term used for a mixture of elements (but I could be wrong)
Lead definitely melts at 467...so does tin and other elements.
Either way there's a lot of volcanic activity on the surface of Venus and has been for thousands of years...
It's a planet best described as hell.
Acid clouds, burning sulphur, no oxygen and etc.
Yes, of course, it's currently speculative; but the fact that measurements suggest that life-as-we-know-it could survive in Venus' atmosphere should boost our Bayesian priors for the possibility of life there.We have the benefit of knowing extremeophiles exist on Earth as well as their biochemical activity.
The only way we will prove their existence on Venus is through direct detection.
Despite the process of elimination of non biochemical processes as being potential sources of phosphine on Venus, there remains the possibility of some unknown mechanism.
One can draw parallels with the mysterious element Nebulium.
Helium was discovered as a spectral line in the Sun's chromosphere before its discovery on Earth which was a success for remote observation.
Remote observations however can also lead to wrong conclusions.
The OIII spectral line in emission nebulae was wrongly attributed to an unknown element named Nebulium in the 19th century.
Nebulium turned out to be being a quantum mechanical "forbidden" transition of the doubly ionized oxygen atom O²⁺ which can only exist in the extreme vacuum of outer space due to low collision rates between atoms.
My father is a chemist.Interesting ..
Just reading through one of key the reference papers behind Venus discovery paper, ie:
Phosphine as a Biosignature Gas in Exoplanet
it says (my underlines):
Interesting!
This whole exercise looks like a hunt to firmen up the environmental constraints under which phosphine can exist in exo-planetary atmospheres, in pre-emption of upcoming James Webb space telescope surveys.
Also, in the light of there being no known (demonstrated) metabolic pathway for its production by Earth-life, (ie: hypothesised only), the idea of the validity of it necessarily being an exo-planetary atmospheric biosignature, is what's really being probed and tested out on Venus' atmosphere(?)
"The astronomers say that it's extremely hard to make phosphine without lifeforms. They are misinformed..." -- (a chemist who has actually made phosphine by accident once, since it's not at all hard to do...)
Having read the article, including it's caveats, but also noticing it's suggestive direction (they plausibly, reasonably point out that their little group couldn't figure out how it could be made in sufficient quantity inorganically...Ok..., it should be no offense to point out that's not saying much, really, about whether it could be made inorganically. Merely that they didn't figure it out yet. While I actually think organisms delivered from Earth via meteorite (via Earth impacts and ejecta) is quite plausible....well, an extrodinary suggestion is...just an extrodinary suggestion.)Sentence 2 of OP
On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.
[my emphasis.]
Extremophiles which survive in acidic environments such as Bacillus do so by becoming dormant.Yes, of course, it's currently speculative; but the fact that measurements suggest that life-as-we-know-it could survive in Venus' atmosphere should boost our Bayesian priors for the possibility of life there.
If evidence of present or past life was discovered on Venus or Mars, I'd put a higher probability on it being Earth-like than not - it's possible that organisms could have been exchanged between Earth, Venus, and Mars (when the latter two were in their more habitable phases).
Why is it so important to do that?Yes, of course, it's currently speculative; but the fact that measurements suggest that life-as-we-know-it could survive in Venus' atmosphere should boost our Bayesian priors for the possibility of life there.
Well of course you would! 'Earth-like life' is what defines 'life', and we can't test for any other kind!FrumiousBandersnatch said:If evidence of present or past life was discovered on Venus or Mars, I'd put a higher probability on it being Earth-like than not -
.. well if we're arguing possibilities, then we should also take into account the 'life not there' possibility, by recognising an as yet unknown process, which could be producing atmospheric Venusian phosphine (which is also 'possible').FrumiousBandersnatch said:- it's possible that organisms could have been exchanged between Earth, Venus, and Mars (when the latter two were in their more habitable phases).
LINK
An international team of astronomers, led by Professor Jane Greaves of Cardiff University, today announced the discovery of a rare molecule – phosphine – in the clouds of Venus. On Earth, this gas is only made industrially, or by microbes that thrive in oxygen-free environments.
Astronomers have speculated for decades that high clouds on Venus could offer a home for microbes – floating free of the scorching surface, but still needing to tolerate very high acidity. The detection of phosphine molecules, which consist of hydrogen and phosphorus, could point to this extra-terrestrial ‘aerial’ life. The new discovery is described in a paper in Nature Astronomy.
Massachusetts Institute of Technology scientist Dr William Bains led the work on assessing natural ways to make phosphine. Some ideas included sunlight, minerals blown upwards from the surface, volcanoes, or lightning, but none of these could make anywhere near enough of it. Natural sources were found to make at most one ten thousandth of the amount of phosphine that the telescopes saw.
No doubt many different experts will kick the tires on this, but the basic result seems sound, while attributing it to life on Venus is a larger stretch that will likely require some kind of independent verification for it to really catch on.
The greater the likelihood of finding life, the greater the likelihood of funding for further investigation.Why is it so important to do that?
Life is not well-specified. There's a whole field of astrobiology or xenobiology concerning life that is not specifically Earth-like, and a variety of definitions of life, including NASA's, “... a self-sustaining chemical system capable of Darwinian evolution”, which, although broad, is considered too restrictive by many. Like Wittgenstein's 'game', many see 'life' as a family of resemblances rather than a well-defined set.Well of course you would! 'Earth-like life' is what defines 'life', and we can't test for any other kind!
If one goes looking for something well-specified, and imagines finding that, then its obvious what one will find, if its there, will be that thing!
Apologies if this sounds circular .. but that's the whole problem, in a nutshell, with the hunt for pre-specified 'life elsewhere'.
Of course - who said otherwise? It would be fascinating to find a natural process by which phosphine could be produced without life being involved... well if we're arguing possibilities, then we should also take into account the 'life not there' possibility, by recognising an as yet unknown process, which could be producing atmospheric Venusian phosphine (which is also 'possible').
(Or, prioritising a Venusian atmospheric probe mission over other competing outer solar system exoplanetary research missions).The greater the likelihood of finding life, the greater the likelihood of funding for further investigation.
Yep .. all highly speculative 'specifications' and yet they have somehow found their way into NASA's Strategic guidelines, courtesy of the topic of 'Astrobiology' .. (y'know the field looking to find evidence for its own existence ..).FrumiousBandersnatch said:Life is not well-specified. There's a whole field of astrobiology or xenobiology concerning life that is not specifically Earth-like, and a variety of definitions of life, including NASA's, “... a self-sustaining chemical system capable of Darwinian evolution”, which, although broad, is considered too restrictive by many. Like Wittgenstein's 'game', many see 'life' as a family of resemblances rather than a well-defined set.
Ok .. just checking. This whole topic of Astrobiology is rife with 'possibility ofs' and 'most likelys'. One has to be careful in separating the scientific thinking from the sc-fi nutter sectarians who seem to not be able to distinguish reality from Star-Trek.FrumiousBandersnatch said:Of course - who said otherwise? It would be fascinating to find a natural process by which phosphine could be produced without life being involved.
Would you have reference for that(?) I'm embedded in reading another study which says that:Extremophiles which survive in acidic environments such as Bacillus do so by becoming dormant.
During this dormant stage the bacteria develops a protective endospore.
.. and how could one not trust a dude with a whopper of a handlebar moustache like that one?sjastro said:.. {YouTube link} ...
With regards to Bacillus.Would you have reference for that(?) I'm embedded in reading another study which says that:
'cellular extracts of Escherichia coli. Acidithiobacillus ferrooxidans have a UV spectrum that is very similar to that of Venus'
.. and then subsequently argues (speculatively) that:
'desiccation in the Venus' atmosphere may be avoidable, despite these low water abundances, due to the hygroscopic nature of sulfuric acid which would likely yield droplets or aerosols containing liquid water, even at high altitudes due to the freezing point depression'.
Link is here.
.. and how could one not trust a dude with a whopper of a handlebar moustache like that one?
Thanks for that.
.. and as you say, the Venusian one appears to be merrily eating and metabolising whilst still in the acidic desiccating environment, so I'm not quite sure of why they bring this example up in the midst of the discussion on dormancy(?) .. (I found that snippet kind of interesting though).The currently held, although highly controversial, record for the longest time spent in suspended animation belongs to the spores of the species of Bacillus sealed in a salt crystal that formed 250 Mya ago (Vreeland et al., 2000). Although so far only one such extremely old example is known and the study is controversial as the age of the isolated bacterium is frequently questioned (Maughan et al., 2002), it suggests that Earth-based bacterial spores may be capable of survival in metabolically inactive states for at least several million years (Cano and Borucki, 1995; Meng et al., 2015).
That's probably what it would amount to...(Or, prioritising a Venusian atmospheric probe mission over other competing outer solar system exoplanetary research missions).
Sounds like you've been reading JohnEmmett's thread on the Mandela Effect...One has to be careful in separating the scientific thinking from the sc-fi nutter sectarians who seem to not be able to distinguish reality from Star-Trek.
The issue is not how Earth based bacteria got to Venus but how they are biochemically active in such a corrosive environment.A way to get organisms to Venus:
Asteroids hit Earth.
Ejecta from impacts escapes Earth and travels through space, with bacteria inside, which can (!) survive remarkable conditions.
Some of the ejecta from Earth arrives on Venus -- that is, generally, meteorites that will break up in the atmosphere, releasing contents directly into the atmosphere.
Questions? Need references for parts of this? It's just stuff I've read from astronomy articles over the years.
@SelfSim
@sjastro
According to Seager, elevation of the dormant spores back to higher and cooler elevations (above the 33-48km layer) is by 'gravity waves'.On Venus this raises another question; what process exists for the environment to change in order for bacteria to exit the dormant phase?
The spores in the lower haze layer must be transported upward to continue their life cycle, but the relative stagnation of the lower haze layer, as described in Section 3.1, creates a challenge. One possible solution is the action of gravity waves, which appear to be present in the lower haze layer due to the layer’s static stability. Although gravity waves can only lead to the net transport of energy and momentum and not matter, they can compress atmosphere layers as they travel and contribute to atmospheric mixing.
The gravity waves could be launched by convective plumes arising in the adjacent (50–55 and *18–28km) convective regions (Schubert et al., 1980; Seiff, 1983; Baker et al., 2000a, 2000b; Lefe`vre et al., 2018). Radio occultation observations found wave-like features in intensity and temperature (Woo and Ishimaru, 1981; Hinson and Jenkins, 1995) that are attributed to gravity waves.
(My underlines).The Venusian spores are likely to have a hydrophilic and hygroscopic exterior so they can attract and absorb both sulfuric acid vapor and water vapor. We note that terrestrial bacteria capture water by using hygroscopic biosurfactant polymers. Many microbial polysaccharides and amphipathic lipopeptides, such as syringafactin, from Pseudomonas syringae have highly hygroscopic properties and are instrumental in reducing the water stress of microorganisms (Burch et al., 2014).
Once self-encased within a H2SO4 and H2O cloud droplet, the Venusian spore would become solvated, eventually leading to the revival and full physiological activation of the cell. On Earth, spores reactivate when the environmental conditions become favorable for active metabolism and growth. The revival of spores occurs on rehydration and subsequent swelling and the reactivation of metabolic activity (Sella et al., 2014).
In the 45-75km altitude range the H₂SO₄ concentration is 73-98%.On the what happens to the hypothetical spore/cell, at altitude, Seager etal also say:
(My underlines).
What they avoid elaborating on here, is what are the effects of the forces imposed on the spore once it absorbs the H2O, in the now even more concentrated H2SO4 surroundings?
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