The Astronomy Thread

[GeoModder]

hi hi

While it's definitely too early to jump to conclusions, I've got a feeling someone will be sending a probe to Venus in the near future to take a closer look.

Possible Marker of Life Spotted on Venus

Here's Putin's chance...
Crash-start a second Venera project.

[Arioch]

Even if NASA decided tomorrow to send new probes to Venus, I think it would take them at least 20 years to actually do it.

Though I'm not sure what kind of probe one would send. They have no idea what they're looking for, and the surface of Venus is not a place where you can just wander around. I think the longest a Venus probe lasted was two hours.

[Jagged]

Though I'm not sure what kind of probe one would send. They have no idea what they're looking for, and the surface of Venus is not a place where you can just wander around. I think the longest a Venus probe lasted was two hours.

They are talking about a layer of the atmosphere where the temperature is more like the Bahamas. So quite nice.

Apart from the clouds being mostly sulphuric acid

ps: Nice to see a post from you. We were collectively worried you were in trouble due to the fires!

[Arioch]

Though I'm not sure what kind of probe one would send. They have no idea what they're looking for, and the surface of Venus is not a place where you can just wander around. I think the longest a Venus probe lasted was two hours.

They are talking about a layer of the atmosphere where the temperature is more like the Bahamas. So quite nice.

Apart from the clouds being mostly sulphuric acid

I'd love to see a probe designed to explore Venus' upper atmosphere, but I fear that all they would be able to find are more tantalizing clues rather than an answer. I think that such a discovery would be awesome, but I'm not sure how they would prove it. It's very difficult to prove the existence of atmospheric life with an unmanned probe, and almost impossible to disprove.

The idea of life arising in an atmosphere is interesting but seems unlikely, as atmospheres are not stable environments. Even if an atmosphere is very dense, and there's a zone that conforms to the "goldilocks" parameters for the genesis of life, atmospheres circulate from the surface to extreme altitudes and back again. Any atmospheric organisms will have to be able to withstand dramatic changes in pressure and temperature as the atmospheric currents circulate them from the highest parts of the troposphere down to near the surface. It seems a nearly impossible setting for life to evolve.

I'd love to be proved wrong in this case, (as it would mean that life is possible even in gas giants) but I don't see how such a hypothesis could be proved or disproved with a probe. Even if the probe finds exactly the chemical signatures it's looking for, it can't be proved that such chemicals must be the product of life. People will have to go there to investigate themselves, and that's not an easy ask.

ps: Nice to see a post from you. We were collectively worried you were in trouble due to the fires!

Thanks. We had a few weird days here with a red sky and the sun being obscured even at midday, but the urban areas of California were not otherwise affected. (Aside from still being under draconian (and unnecessary) lockdown rules that are still in effect here.)

[Krulle]

The idea of life arising in an atmosphere is interesting but seems unlikely, as atmospheres are not stable environments. Even if an atmosphere is very dense, and there's a zone that conforms to the "goldilocks" parameters for the genesis of life, atmospheres circulate from the surface to extreme altitudes and back again. Any atmospheric organisms will have to be able to withstand dramatic changes in pressure and temperature as the atmospheric currents circulate them from the highest parts of the troposphere down to near the surface. It seems a nearly impossible setting for life to evolve.

Earth's oceans have similar mechanisms for algae. The water circulates and kills quite a large prtion of the algae when pulling it down. It never resurfaces. But the algae at the habitable layers reproduce fast enough that life continues.
Now a water circulation is different than an air stream, and floatation is more easily achieved in water than in air, but the same general principles may have resulted in a stable environment. The air circulation may even be necessary as it may bring nutrients or trace minerals into the habitable layer (just like the ocean circulation does).

Unless we can actually find it, and observe it in situ, which is nearly impossible, we will continue to speculate.

ps: Nice to see a post from you. We were collectively worried you were in trouble due to the fires!

Thanks. We had a few weird days here with a red sky and the sun being obscured even at midday, but the urban areas of California were not otherwise affected. (Aside from still being under draconian (and unnecessary) lockdown rules that are still in effect here.)

Good to read you're alive and well.

[Arioch]

Earth's oceans have similar mechanisms for algae. The water circulates and kills quite a large prtion of the algae when pulling it down. It never resurfaces. But the algae at the habitable layers reproduce fast enough that life continues.
Now a water circulation is different than an air stream, and flotation is more easily achieved in water than in air, but the same general principles may have resulted in a stable environment. The air circulation may even be necessary as it may bring nutrients or trace minerals into the habitable layer (just like the ocean circulation does).

Unless we can actually find it, and observe it in situ, which is nearly impossible, we will continue to speculate.

I don't dispute that such a system is possible, or that it might exist on Venus, only whether we could in the near future launch a probe that could reasonably be expected to prove it one way or the other. I have nothing to do with such decisions, of course, but I would be reluctant to spend tens of billions of dollars on probes which would only provide more tantalizing hints rather than evidence that might resolve the issue.

I have developed a pessimistic attitude about the discovery of life in our own solar system, but I would be very pleased to be proved wrong in this respect. But if one really wanted to find life in our own solar system, I think they'd be better off looking for it in places like Jupiter's and Saturn's icy moons rather than Venus.

[Krulle]

I fully concur with you.

I'd also prefer to spend the money we spend on arms on space exploration.
And I agree finding/proving life on Mars, Europa, ... whatever with liquids and rocky "grounds" will likely be much easier and more effective.
But space is big, and everything needs to be lifted first, which makes it fantastically expensive.

Political realities make something else important first...
Si vis pacem, para bellum.
And too many are not just interested in keeping peace but to actively expand their sphere of influence.

Which just proves, that our sun and ehr solar system likely has not brought forward intelligent life yet.

[icekatze]

hi hi

Even if it's not life, it would have to be a chemical process that is new to science, which would still be a pretty amazing discovery.

[Arioch]

hi hi

Even if it's not life, it would have to be a chemical process that is new to science, which would still be a pretty amazing discovery.

Sure, but I wouldn't put it near the top of the list of things I'd like to spend trillions of dollars to discover. We don't know what we're looking for, so we could send billion dollar probe after billion dollar probe and not find anything. The only way to find out for sure would likely be to send a manned mission, or even establish a Venus base. That's quite an undertaking.

I don't mean to sound like a wet blanket when it comes to space exploration, but my view is that space isn't going anywhere. Whatever's producing phosphine on Venus will probably still be there in 50-100 years when we'll have the technology to check it out without mortgaging our grandchildren. I have the same feeling about the urgency of Mars colonization; humanity has survived extinction for millions of years, and a few more decades won't be a significantly statistical additional risk. (Even Elon Musk seems to understand that Mars colonization won't happen until 2050, but he's right that nobody's really been working on the problem for the last 30 years or so... so I'm glad we have him and SpaceX working their tails off to make up for lost time.)

[Krulle]

I agree. We should develop technology on which we can sustain space exploration without bankrupting our economies.

Best would be to stop spending on military, then the money will easily be left, but for that we would need a global agreement, which is unlikely when one of the superpowers operates under a "America first" guideline, and the other two power blocs are busy increasing their sphere of influence, and the fourth power bloc is internally struggling to get to unanimous decisions and basically on the border of being operable at all.

And Elon Musk is an expert in attracting attention and marketing this attention. I don't think his company is really spending that much efforts on their Mars colonisation project. But then, nobody did much with the lifting technologies (rockets), which is a pre for any large-scale space efforts.

[Mk_C]

Best would be to stop spending on military

But the whole context of this here community operates on an implicit agreement that the funniest and most worthwhile thing to do in space is wasting some other fools. Who's gonna do it up there if not the military?

[Zorg56]

We just need to find space whales, because if we do, then very soon entire galaxy will be covered with whaler colonies.

[Arioch]

Best would be to stop spending on military, then the money will easily be left, but for that we would need a global agreement, which is unlikely when one of the superpowers operates under a "America first" guideline, and the other two power blocs are busy increasing their sphere of influence, and the fourth power bloc is internally struggling to get to unanimous decisions and basically on the border of being operable at all.

Humanity has never, in our entire history, been able to operate as a one-world entity. That's primarily because we're not a one-world entity; even conglomerate polities at the scale of the United States or European Union have a difficult time making one law for many diverse peoples with distinct cultural identities that have fundamental disagreements about how to live. Blaming this on specific American or Chinese foreign policy is, I think, overlooking some basic issues of human nature. Humans are social, but inherently tribal... sometimes I'm amazed that we're able to cooperate as well as we do at large scales. I think there may be a limit as to how large our collective governments can get, and least for our present condition.

And Elon Musk is an expert in attracting attention and marketing this attention. I don't think his company is really spending that much efforts on their Mars colonisation project. But then, nobody did much with the lifting technologies (rockets), which is a pre for any large-scale space efforts.

Developing the technology and expertise for cost-effective transport to orbit and beyond is exactly what SpaceX has been doing for the last 18 years... and very successfully. SpaceX has outperformed NASA and all of the traditional aerospace companies (as well as the other new aerospace startups) consistently and by a wide margin on cost, speed, and performance. SpaceX as a startup has developed and flown an all-new-from-the-ground-up reusable space transportation system much faster and better than NASA's established aerospace contractors could develop its completely-rehashed-off-the-shelf-technology-for-easier-development non-reusable system... to say nothing of SpaceX's parallel development of their next generation all-reusable superheavy lift vehicle ultimately intended for Mars missions. Give the man some credit where it's due.

[Ithekro]

I would mark that up as Musk not having to come up with a military use for his hardware to justify costs to Congress and conduct work on the exploration side materials as the public side project for military development projects. The US Navy was designing a moon lander at China Lake before the project was given to NASA (the Navy seeing it as a public relations stunt, as getting a man to the Moon before the Soviets using NASA would be more rewarding publicly (and privately thumbing the nose at the Soviets with it) than having it be a strictly military project.

[Werra]

Sadly, we need a military and a certain ruthlessnes to concentrate material wealth to such a degree that resource heavy investments like space habitats are possible.
Once the bobsled ride down the EROI cliff of crude oil starts, a lot of frivolous projects will need to be reconsidered.

Space exploration is all well and good, but the past century was a big exception in human history. Space will need to provide a return on investment that can be quantified in resources to justify the associated energy costs. I have my doubts on how viable a Mars colonization would be in terms of resources.

[Ithekro]

All that needed is a way to make if profitable, and/or viable as trade. Even if it is mostly trade between various colonies, with only monetary/technological trade back to Earth (or "rare" something or other that gets a good price Earthside). Than its is sustainable if the commerce is basically moving needed resources from one point to another around the Solar System to support life in those place. Even if mostly all the trade is just to keep those colonies alive early on, that is a step forwards. It could take a hundred or two hundred years to get them to a point where they are doing anything but survival trade economies, but eventually, they should become viable on their own.

[Arioch]

Space exploration is all well and good, but the past century was a big exception in human history. Space will need to provide a return on investment that can be quantified in resources to justify the associated energy costs. I have my doubts on how viable a Mars colonization would be in terms of resources.

That's one of the things I like about SpaceX's Mars plan: it's privately funded. As long as they're not using my tax dollars for it, they can be as frivolous as they want in their space ambitions.

[Incinerator]

That's one of the things I like about SpaceX's Mars plan: it's privately funded. As long as they're not using my tax dollars for it, they can be as frivolous as they want in their space ambitions.

Well, they could be using your retirement fund instead. Alphabet (Google's parent company for those unaware) owns a $900m share of SpaceX. If your retirement fund manager has invested in Alphabet, and I bet very many have, you're still exposed to the risks.

It's a drop in the bucket when compared to Alphabet's nearly one trillion dollar market cap though. Even if SpaceX folds overnight, it's probably not going to affect most people that aren't Elon Musk, an employee or other direct investor. Just some food for thought.

[Arioch]

I don't have a retirement fund, so that's someone else's problem.

I think SpaceX is a smart investment, but that's easy to say without skin in the game.

[Werra]

All that needed is a way to make if profitable, and/or viable as trade. Even if it is mostly trade between various colonies, with only monetary/technological trade back to Earth (or "rare" something or other that gets a good price Earthside). Than its is sustainable if the commerce is basically moving needed resources from one point to another around the Solar System to support life in those place. Even if mostly all the trade is just to keep those colonies alive early on, that is a step forwards. It could take a hundred or two hundred years to get them to a point where they are doing anything but survival trade economies, but eventually, they should become viable on their own.

There are two economies that are closely linked, but not congruent. On one hand, there is the economy in monetary terms. In that market, space exploration can be made profitable with fiscal or technological trade. The other economy trades in resources. Westerners aren't for the most part aware of its existence, because we did live in unparalleled surplus for the last century.
A lot of people think that when oil deposits get rarer, price for oil will rise and make exploiting more challenging deposits worthwhile and thus the supply of oil and energy will remain the same. However, we need resources for this exploitation, meaning the EROI keeps sinking. The danger of a low EROI is that we can be lacking the energy surplus to maintain higher industry, extensive schooling or the ability to feed the population. We've had an EROI of 100 barrels/barrel in 1900. It's fallen now to 14 barrels/barrel. The effects of this aren't linear, from 100 to 20 is only a reduction from 100% to 95%. The change from 10 to 9 however can be massive.
To get to the point of my depressive post, we might not have a century left in us to get projects up and running that do not provide a quick benefit in resources.

So the best way to make space exploration sustainable would be to find ways of harvesting energy in space and sending it back down to earth. Perhabs LEO based solar farms tethered by a space elevator/power line could be worth it. Or harvesting fissible materials in asteroids and planetoids and using those to sustain our dependency on artificial fertilizer.