Venus could have been habitable for billions of years (2019) • Hacker News Board

Re: Venus could have been habitable for billions of years (2019)

#231

Post by userulluipeste » Thu, Mar 25, 2021, 12:46 AM UTC

howlin wrote: post #112

01100011 wrote: post #55

And it could be again... I wish we would plan ahead and try a solar shield at L1. If we cooled the planet sufficiently, the CO2 would solidify and we could get to work processing it. Venus is far more interesting than the dusty little rock we keep probing. Sure, it may take a millenium, but the sooner we start, the sooner we finish.

Venus has lost almost all of its atmospheric hydrogen. Teraforming a planet like this to sustain life would be quite a challenge. Here's an excerpt from the wikipedia page ( https://en.wikipedia.org/wiki/Terraforming_of_Venus ) Difficulties include the fact that the production of organic molecules from carbon dioxide requires hydrogen, which is very rare on Venus. Because Venus lacks a protective magnetosphere, the u…

"Because Venus lacks a protective magnetosphere, the upper atmosphere is exposed to direct erosion by the solar wind and has lost most of its original hydrogen to space."

Venus has a magnetosphere, although not as strong as Earth's. The problem with Venus' atmosphere, AFAIK, is that the heavier carbon dioxide layer is so thick that reaches the limit of that magnetosphere and in doing so it pushes the lighter molecules like hydrogen or even water to be exposed to the mentioned solar wind. If enough of that atmospheric carbon gets somehow fixated, then the freed oxygen should act as a capture net for all the solar wind's incoming protons and form water molecules (which, being heavier than oxygen, should then sink into lower atmospheric layers).

P.S.: I assumed only "enough" of carbon taken out of the atmosphere, so enough carbon dioxide should be assumed as left there untouched, which now with newly available water molecules should result in bicarbonate, carbonic acid, and other goodies, thus preserve Venus' traditional acidic environment, so no worries there! ;)

Re: Venus could have been habitable for billions of years (2019)

#232

Post by gdubs » Thu, Mar 25, 2021, 3:49 AM UTC

elihu wrote: post #11

xwdv wrote: post #2

That’s enough time for a civilization to have been born, lived, and died. Unfortunately there’s probably no way to find evidence of their existence by now it seems? Some day they may say Earth could have been habitable for billions of years.

If there was a civilization on Venus anything like our current civilization on Earth, I expect there would still be evidence of it, even in that hostile environment. If nothing else, there'd probably be unnatural formations of ground from mines or freeway construction or whatever.

A couple of NASA scientists published a paper on this a little while back and apparently we’d have a hard time even detecting a previous advanced society on earth. Pretty mind blowing. I often wonder if Venus had an industrial society that set off a runaway greenhouse effect.

Re: Venus could have been habitable for billions of years (2019)

#233

Post by gear54rus » Thu, Mar 25, 2021, 1:21 PM UTC

messe wrote: post #212

bregma wrote: post #173

Earlier quoted context omitted.

It lasted what, 8 seconds before transmission ceased? It was definitely a success since they expected it to last about 5 seconds.

You're probably joking, but I'll post this comment anyway, as the Venera program was actually quite impressive. Venera 7 lasted 23 minutes before failing (although landed in an awkward orientation due to parachute failure). Venera 8 transmission for nearly an hour, but wasn't equipped with a camera. Venera 9 operated for 53 minutes, had issues with the lens cap so only took pictures from one of the cameras. Venera 10…

The last one is facsinating... the sheer amount of stuff that can go wrong on a mission like this is mind-boggling.

Also the frustration they must've felt seeing the same lens cap malfunction over and over.

Re: Venus could have been habitable for billions of years (2019)

#234

Post by plank_time » Thu, Mar 25, 2021, 10:23 PM UTC

dredmorbius wrote: post #230

plank_time wrote: post #185

Earlier quoted context omitted.

> asteroid hypothesis for the mass extinction of the dinosaurs have passed from wild theory to accepted fact We should NEVER accept a hypothesis as fact because that makes people stop thinking or searching for answers. And there’s no way we can even definitively say something that happened tens of millions of years ago actually happened. I personally think it was an asteroid too, but I never want to be arrogant enoug…

We can of course continue to look for disconfirming evidence, alternate explanations, or Incontrovertible Signs That God Is A Prankster, but come a certain point and the focus becomes one of refining rather than overturning theories and models.

It’s rather arrogant as a species for us to believe that enough evidence remains tens of millions of years after something like that happened that we can come to a conclusion. For all we know, a pandemic could have swept across the globe and killed all the dinosaurs and there would be no way for us to detect it.

Re: Venus could have been habitable for billions of years (2019)

#235

Post by eloff » Fri, Mar 26, 2021, 3:33 AM UTC

mrkstu wrote: post #76

eloff wrote: post #28

Earlier quoted context omitted.

Why move earth when you could just throw up some shade? By then things would be so different it's impossible to imagine what humans might do or be capable of our interested in - if we're still around.

Shade won’t help much when the sun is a red giant star…

Why not? Shade continues to function the same.

If placed at the Lagrange point between Earth and the Sun (supposing that's not too close to said red giant), you wouldn't even need that much.

Re: Venus could have been habitable for billions of years (2019)

#236

Post by dredmorbius » Fri, Mar 26, 2021, 5:12 PM UTC

plank_time wrote: post #234

dredmorbius wrote: post #230

Earlier quoted context omitted.

We can of course continue to look for disconfirming evidence, alternate explanations, or Incontrovertible Signs That God Is A Prankster, but come a certain point and the focus becomes one of refining rather than overturning theories and models.

It’s rather arrogant as a species for us to believe that enough evidence remains tens of millions of years after something like that happened that we can come to a conclusion. For all we know, a pandemic could have swept across the globe and killed all the dinosaurs and there would be no way for us to detect it.

Occam's razor suggests:

1. Such a pandemic (or other calamity) occurring simultaneously with overwhelming evidence a catastrophic asteroid impact is exceedingly unlikely.

2. Cross-species pandemic resulting in mass extinctions are similarly unlikely. Boom-bust population cycles perhaps. Mass cross-species extinction not so much.

3. Patterns of extinction (and survival) far more closely match the presently-accepted conclusion.

4. Precisely because an infectious agent leaves few multimillion-year traces, any defence of such a hypothesis can advance no further than "it might have happened". This is not evidence-based argument. (Traces of pathology might be preserved in fossil or amber substrates.)

Point remains that multiple highly consistent widely-distributed lines of evidence point to the asteroid hypothesis.

One unsubstantiated Hacker News comment points to the epidemic scenario.