Possible life discovered on Venus?

[Valandil]

9 minutes ago, IheartIheartTesla said:

And then there's this:

I wouldnt spend billions of dollars on such a lukewarm result. Maybe if we saw a bit more direct evidence like actual microbes, or even lipids, DNA/RNA strands etc.

But how are you going to see those without sending a probe? We aren’t going to see DNA from here. 

[S John]

58 minutes ago, IheartIheartTesla said:

And then there's this:

I wouldnt spend billions of dollars on such a lukewarm result. Maybe if we saw a bit more direct evidence like actual microbes, or even lipids, DNA/RNA strands etc.

Personally, I think it’s worth it, this is just the sort of thing NASA and other international space organizations should be doing. Yea, it would take a major undertaking to enter the atmosphere and recover a sample and have that probe live to tell about it. I’m not even going to begin to speculate as to how that might be done, but I think that the science question at the center of the undertaking is totally worth it. 

[Werthead]

Venus has been underrated for exploration, especially given the growing mountain of headaches when it comes to settling on and colonising Mars, where every year it seems we get further away from actually doing something there. Although at least we can land on Mars, whilst with Venus all we can do is float in the atmosphere, which is more logistically punishing.

[IheartIheartTesla]

1 hour ago, Valandil said:

But how are you going to see those without sending a probe? We aren’t going to see DNA from here. 

Phosphine gas is much smaller in terms of length scale  and we didnt need to send a probe.. I'm just guessing, but if the P-H bond was discovered using some sort of spectrum, then these other materials would also have should also unique signature that may be discoverable

[S John]

55 minutes ago, IheartIheartTesla said:

Phosphine gas is much smaller in terms of length scale  and we didnt need to send a probe.. I'm just guessing, but if the P-H bond was discovered using some sort of spectrum, then these other materials would also have should also unique signature that may be discoverable

I admit to not having dug beyond surface level as presented in this thread but I would almost guarantee they used spectral imaging to make the determination that there was phosphine in the atmosphere. At the distances in play I don’t know how else they might have done it, but I’ll allow that they may have had some method I don’t know about. A fly-by reconnaissance mission in order to increase the resolution to look for additional bi-products may be the appropriate middle ground. Send something that can orbit Venus loaded with the appropriately high spectral and spatial resolution sensors to detect if any of the more elusive by-products might be picked up at close range. Beam those images back to earth and if that looks promising send a probe.

[The BlackBear]

2 hours ago, IheartIheartTesla said:

I wouldnt spend billions of dollars on such a lukewarm result. Maybe if we saw a bit more direct evidence like actual microbes, or even lipids, DNA/RNA strands etc.

I think it's worth mentioning we're not just firing cash into the atmosphere, the money is going towards development that will likely help all space exploration. If a probe is sent to Venus, this would only be a part of it's brief, they'd want to get as much info as possible on the planet.

[ithanos]

Curious, there was a podcast recently from Lex Fridman, with Sara Seager as the guest. Sara Seager is an astrophysicist and planetary scientist at MIT. After listening to the podcast Seager became one of my favourite scientists and one who's research is worth watching.

On professor Seager's website, in the Exoplanet Biosignature Gases page, there's a link to one of her papers;

https://www.saraseager.com/wp-content/uploads/2020/07/Seager2013a.pdf
 

Quote

 

...Some (PH3, SiH4) require energy input to make the reduced product from geologically available materials and so would not be produced by Type I biosignature gas reactions...

...As an aside about phosphine (PH3), we note that trace amounts of phosphine are produced by some anaerobic ecologies on Earth (Glindemann et al.2005). It is controversial whether the microorganisms in these environments are making PH3 or whether the bacteria are making acid that is attacking environmental iron that contains traces of phosphide and this attack is making the phosphine gas (Roels & Verstraete 2001). Phosphine is a potential biosignature in other highly reduced environments. Phosphine is reactive and thermodynamically disfavored over elemental phosphorus and hydrogen at the surface pressure and temperature of the Earth. Phosphine might be a Type I biosignature gas under conditions of very high H2 pressure, which would favor the production of PH3 over elemental phosphorus. Phosphine could be also be produced as a Type III biosignature gas, analogous to reactive signaling molecules suchas NO or C2H4 on Earth.

 

 

[IheartIheartTesla]

16 hours ago, The BlackBear said:

I think it's worth mentioning we're not just firing cash into the atmosphere, the money is going towards development that will likely help all space exploration. If a probe is sent to Venus, this would only be a part of it's brief, they'd want to get as much info as possible on the planet.

Of course I agree we should send probes wherever we can with however much money we can afford. Just asking for a little honesty in advertising is all, particularly from administrators using the public dime and making wild-ass statements.

I guess the part that is annoying about all this is the lack of acknowledgement of just how many complex intermediate steps have to occur to note that microbes created phosphine. First, microbes have to evolve on Venus (this isnt a simple thing for starters, the conditions on Venus or its atmosphere and the primordial ooze of Earth are presumably quite different and who knows what pathway life on Venus would take). Second, they have to evolve to a form that is relatively similar to the same single celled organisms on Earth. Third, these organisms need to have similar biological functions under extreme conditions as the ones on Earth. I mean, the more I think about it the more it annoys me that Occam's razor has not been applied here. Thats my rant for today, but that we can measure ppb of a gas on a planet many, many miles away is to me is the most remarkable/cool part of this story.

[DireWolfSpirit]

Just reading interesting article about Sagan predicting in 1967, that the upper atmospheres of Venus would likely show signs of life.

https://mashable.com/article/venus-life-theory-carl-sagan/

[Werthead]

The BBC Sky at Night dedicted a half-hour to the discovery and went into it in some depth. They confirmed the discovery with two different telescopes and modelled how phosphine is produced by non-life-producing means. The best result they could come up with would produce only 1/10,000th the amount of phosphine they are seeing in the atmosphere. Based on their modelling, the sulphuric acid in Venus's atmosphere will degrade and destroy phosphine in the atmosphere within hours, so something has to be constantly producing it.

They note that it's not quite the smoking gun for life but the only alternative is that there is some process native to Venus but not Earth which can naturally, constantly generate phosphine on a scale never before seen, something still of remarkable scientific interest (if with a much less sexy headline).

[Starkess]

This is really exciting news! Of course this isn't a confirmation of life, but it's an unexpected and intriguing result.

Phosphine had previously been identified as a possible biosignature in a relatively compelling way. This observation was originally just to benchmark what the phosphine line would look like in Venus--the actual detection was a big surprise! It was also confirmed with a second telescope. However, while it seems to be a robust observation, it *is* based on a single line only. Next best step IMO is to get some multi-line observations--not really possible from the ground (thanks, atmosphere), but could be done from space observatories. And Venus had already been up for several NASA proposals--already a desirable target before this and now I think even more compelling. In situ measurements will be very important.

It's possible and even likely that this is some sort of abiotic source. But to be clear, there is *no* known process that can explain this amount of phosphine right now. So no matter what, we'll learn something new if we can identify the source. And knowing the abiotic process happening here will help avoid false positives in detection biosignatures on exoplanets.

So yes, this is a really great discovery and, while "ALIENS!!" is obviously an overreaction, excitement/curiosity is not.

[Werthead]

The researchers note they have a problem that so many telescopes are designed to peer billions of light-years away and detect very sensitive, tenuous traces, so training them on Venus is the equivalent of aiming one of those audio-detecting sensors on a heavy metal concert, or peering down an optical telescope at the Sun. If anything, they need less sensitive equipment to help parse out out the noise.

Further follow-up studies are of course planned.

[DireWolfSpirit]

 

[Starkess]

3 hours ago, Werthead said:

The researchers note they have a problem that so many telescopes are designed to peer billions of light-years away and detect very sensitive, tenuous traces, so training them on Venus is the equivalent of aiming one of those audio-detecting sensors on a heavy metal concert, or peering down an optical telescope at the Sun. If anything, they need less sensitive equipment to help parse out out the noise.

Further follow-up studies are of course planned.

Yep definitely, telescopes are designed with a certain focal length so you can't just point them at anything for optimal results. But there are several ongoing missions that should have some capacity to observe Venus from space, and my understanding is that it doesn't need to be super high resolution as long as it can see the relevant wavelengths (that are blocked by the Earth's atmosphere). But I should clarify that I am *not* an observer so I have only a passing knowledge of these things!