Is there life floating in the clouds of Venus?

[Biskit]

This just popped up on the BBC - phosphine in the Venusian atmosphere and so far there's no explanation for how it gets there other than living organisms. (Admittedly, mostly they're saying there must be some other chemical pathway they've overlooked, but it's still a bit of a wow.)

Is there life floating in the clouds of Venus?

 

[Ori Vandewalle]

This is a very cool finding, but I'm definitely skeptical it means there's life on Venus. As I see it, there are four hurdles to overcome before even tentatively reaching that conclusion:

1. Is the signal real? It's a difficult measurement to make. They looked at emissions from a deep, dense, opaque part of Venus' atmosphere and then analyzed patterns of absorption in that emission. Doing that requires modeling a layer of the Venus atmosphere and then subtracting that model from the data to see what's left. But Venus is notoriously understudied and difficult to study, so there's definitely room for error in there.

2. Is the signal phosphine? Again, seeing through the atmosphere of Venus is hard, so it's difficult to conclude the absorption line is definitively phosphine as opposed to either (a) a chemical with a nearby spectral line or (b) something entirely unaccounted for in the atmosphere.

3. Does phosphine mean life? Phosphine exists elsewhere in the solar system (in gas giants) for entirely abiotic reasons. It's thought to be unlikely near the surface of a rocky world because it's hard to get phosphorus up into the atmosphere and because phosphine itself shouldn't last long in that kind of environment. So it's known that life can produce enough phosphine to balance out how quickly it's gotten rid of, but there's not yet a known mechanism from via geological or other processes for doing so.

4. Is life on Venus plausible? I think your prior on this has to be low just on the basis of what we know about life on Earth. There's life everywhere on our planet, even in very harsh conditions, but we don't know that life can originate under such conditions. And Venus is a really terrible place. So this is a "extraordinary claims require extraordinary evidence" kinda thing.

 

[mosaix]

Sky At Night on BBC4 discussing it now.

They seem very excited about it.

Some points from the program:

Signal detected by two different telescopes.

No signal in the polar regions.

Known non-life generating mechanisms for producing phosphine are 10,000 times too week to produce the volumes identified.

 

[Robert Zwilling]

I think it would be extraordinarily funny if some kind of life from Earth got transported to Venus on one of the many probes and satellites sent there and found it a really nice place to live after having gone through all those hurdles on its way to get there. Telltale biological markers exist but which is more likely in this case? That the markers on one planet which is completely different from the other planet would be the same or that the markers are the same on 2 completely different planets because of contamination? One interesting thought is that kind of life we are familiar with might be more at home at the top of Venus's atmosphere where it is cooler and the concentrations of substances are much lower than at the surface.

 

[-K2-]

I have a feeling that as long as we continue to look for life elsewhere--as we know it to exist in our world, instead of looking for different forms of life--we'll live a lonely existence for a very long time.

K2

 

[TheEndIsNigh]

We're doomed!​

They've been building their invasion force for over fifty years now. Ever since some idiot thought it was a good idea to send a probe to Venus. Prior to that they thought the prospect of anything coming from Earth, was a million to one.

No doubt, one of the first attempts at landing on Venus caused devastation and interplanetary war became inevitable. I can imagine the rage in some Venusian war council as they mourned the loss and death of people caused by our childish attempts.

Now it seems the signs of the war machine they are assembling can no longer be contained. We can expect the attack any time.

To far fetched you say.

What do you suppose we would be doing if the roles were reversed?

Imagine it, a lump of space junk plummets to Earth destroying Las Vegas? The outrage and bellowing for all out vengeful war would be echoing down the decades until we mounted our merciless retaliation with the intent of wiping out every living being on the planet of love.

** Blue-hey as they no doubt call it in their guttural whining - There can't be life on that world it's full of water and the temperature is so cold, CO2 heat exchanging lungs could never survive.

 

[-K2-]

They've been building their invasion force for over fifty years now.

Those devils...they're coming for our acid rain.

K2

 

[J Riff]

ah, here we go with Venus now, finally. Up next - Saturn!

 

[Brian G Turner]

That's really, really interesting - the idea of life in the clouds of Venus is old - I think Carl Sagn discussed that back in the 70's. However, phosphine had recently been flagged as a potential bio-marker when looking at exoplanets: Smelly, poisonous molecule may be a sure-fire sign of extraterrestrial life

 

[paranoid marvin]

Well, I for one welcome our new Venusian overlords.

 

[nixie]

its not real.


(hopefully they will believe me, dont want my amazing holidays ruined, I visit Venus twice a year, no tourists to spoil my enjoyment)

 

[Ori Vandewalle]

I have a feeling that as long as we continue to look for life elsewhere--as we know it to exist in our world, instead of looking for different forms of life--we'll live a lonely existence for a very long time.

K2

Most biosignatures astronomers looks for are either complex chemicals or large quantities of chemicals that should decay rapidly in a given environment. Life on Earth serves as a starting template for the kinds of physical/chemical/biological processes we know exist and meet those criteria. Lots of highly reactive O2 in the atmosphere = photosynthesizing plants, etc.

If you widen your search criteria too far, I think you reach a point where it becomes impossible to conclude one way or another whether you've found life, because you have nothing to compare it against.

 

[Brian G Turner]

Phil Plait gives a heads up that volcanoes can be a source of phosphine: Life in hell: Could Venus have a bacterial infection?

This could be important, because it's coming to light that we've probably underestimated volcanic activity on Venus. Even still, even that might not be enough to account for the concentrations of phosphine discovered.

What really, really, surprises me is that no one has apparently taken spectra of the planets and run thorough analysis of all the signatures found. I always presumed that must already have happened - but this story wouldn't be news today if it had already been done.

 

[Ori Vandewalle]

What really, really, surprises me is that no one has apparently taken spectra of the planets and run thorough analysis of all the signatures found. I always presumed that must already have happened - but this story wouldn't be news today if it had already been done.

Hard to do, unfortunately, for a variety of reasons. For planets with atmospheres, you have to consider all the intervening layers that might get in the way. And if you're a ground-based observatory, you have to contend with Earth's atmosphere. You can use space telescopes, but most of them are designed for observation beyond the solar system and can run into trouble looking at big bright planets. Probes sent to particular planets will work, of course, but they're always designed with efficiency in mind and specific mission goals, so they might not have broad spectrum capabilities.

 

[M. Robert Gibson]

Now it seems the signs of the war machine they are assembling can no longer be contained. We can expect the attack any time.

We can only hope they miscalculate the scale and their entire battle fleet gets accidentally swallowed by a small dog.

 

[Stephen Palmer]

I think it would be extraordinarily funny if some kind of life from Earth got transported to Venus on one of the many probes and satellites sent there and found it a really nice place to live after having gone through all those hurdles on its way to get there. Telltale biological markers exist but which is more likely in this case?

Transports from Earth, I reckon. Those unclean '60s/'70s probes...

 

[Ray Zdybrow]

4. Is life on Venus plausible? I think your prior on this has to be low just on the basis of what we know about life on Earth. There's life everywhere on our planet, even in very harsh conditions, but we don't know that life can originate under such conditions. And Venus is a really terrible place. So this is a "extraordinary claims require extraordinary evidence" kinda thing.

We don't know how (or even if) life originated on Earth. But anyhow, perhaps life originated (or arrived) on Venus at a time when it was more hospitable, and managed to hang on, adapting to its changing conditions? The folks at Cardiff seem to think that there IS extraordinary evidence - they haven't been able to come up with any other plausible hypothesis to explain the results. Anyways I must go now to watch "The Sky At Night"!

 

[paranoid marvin]

Cynical me says it gets space back in the headlines and perhaps bigger funding for more projects. Tbh after 6 months of wall-to-wall Covid coverage it's a hugely welcome relief.

 

[Ori Vandewalle]

We don't know how (or even if) life originated on Earth. But anyhow, perhaps life originated (or arrived) on Venus at a time when it was more hospitable, and managed to hang on, adapting to its changing conditions?

Sure, but I think it's reasonable to put a lower prior on that than the hypothesis that life originated on the planet where it's known to be abundant.

The folks at Cardiff seem to think that there IS extraordinary evidence - they haven't been able to come up with any other plausible hypothesis to explain the results.

I wouldn't say they're claiming to have extraordinary evidence for life. From their paper:

Even if confirmed, we emphasize that the detection of phosphine is not robust evidence for life, only for anomalous and unexplained chemistry. There are substantial conceptual problems for the idea of life in Venus’ clouds – the environment is extremely dehydrating as well as hyperacidic.

 

[Ray Zdybrow]

They seem to be saying they have extraordinary evidence - for some type of chemical reaction we don't understand, or for life, but again we don't understand how it could survive.
Top marks for reading the paper, I just watched the programme!