Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

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

smithsonianmag.com

Post reply on HN
Print view View original

131–140 of 236 posts

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

#131

Post by dimitrios1 »

galaxyLogic wrote: post #99
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.

> And it could be again... It could. On the other hand Earth could become the next Venus, if climate change runs out of control. No?

No.

For one, Earth is much further away.

But most importantly, we have no clue if our current carbon levels are any sort of maxima in regards to what the planet can handle. We just have our own little recent industrialized history, and some charts about the past that are, at best, educated guesses.

As George Carlin would say, "The planet will shake us off like a bad cold"

Climate change is more important for our species survival much more so than the planet. The planet will be fine. The planet will recover after we're gone.

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

#132

Post by ramraj07 »

swagasaurus-rex wrote: post #113
ReaLNero wrote: post #105

Earlier quoted context omitted.

Wow, that's... actually pretty sensical. The science part of me rejects it for having no evidence. But the pragmatic part of me would put its money underneath the theory. The reason The bigger question is: how did the first Protozoa form? The usual primordial soup theory of random chance? One good thing about this theory is that if there are 10^7 habitable planets at any given moment, each of them are "trying to prod…

So evidence pointing towards a common ancestor for all life here on Earth, or at least very similar common ancestors, might imply that of a seeding event, there wasn't much variety. However, if we assume a seeding event happened, what's to say it couldn't happen on a lot of planets around the same area at the same time? The Fermi paradox is too speculative to say we aren't the only ones. One thing that's missing is a…

I am curious if floating microbes in our atmosphere can just randomly leave the planet - like are particles small enough to undergo Brownian motion subject to the same escape velocity ?

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

#133

Post by chii »

flawi wrote: post #119
tsimionescu wrote: post #106

Earlier quoted context omitted.

Terraforming refers to 'turning another planet into a second terra'. Marsforming would be 'turning the planet into a second Mars', which wouldn't be particularly useful, since we can't live on Mars anyway.

The joke they're making is that since we are in the process of turning the Earth into a second Mars, we should be calling what we are doing now marsforming.

i think you'll find that venus is the place with the runaway greenhouse effect, not mars!

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

#134

Post by montychain »

ncmncm wrote: post #91
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 is interesting in so many ways. It did not, so far as we can tell, get blasted by a Mars-sized proto-planet like Earth did, which made the Moon and entirely re-melted Earth, so probably got a good head start on breeding life. But maybe Earth's plate tectonics came from that event, too. AIUI, our Moon is also the reason we are not tidally -almost- locked to the sun, with a permanent equatorial 250 mph wind.

If Venus wasn't hit with something massive why the weird backwards and slow rotation that no other planet has?

I feel like even if Venus had Earth-like atmosphere it'll still be hard for life to endure the 121-day long "day" and "night" where temperature would go from like 250°C to -250°C (numbers from the top of my head). Maybe only on poles there would be possible for water to stay in liquid form for long enough so that life could emerge.

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

#135

Post by brnt »

protoman3000 wrote: post #117

I recently learned about the estimated age of the universe. It’s only 13.8 billion years. So when it says Venus was hospitable for billions of years, let’s say 2 billion years, that amounts already to 14% of all there was and will ever be. What marvel did happen in this time?

We've had life for about 500 million years on earth. Maybe a billion as single celled life forms. I used to worry that in 5 billion years it'll all be over on account of the sun entering a new phase and engulfing Earth. But it appears in about 800 million years photosynthesis will no longer be possible [1], which puts an even closer limit on our time here. There's a good chance some will get off this rock, but many won't. And all that we know will be lost, and we'll need space suits to visit, no more nature to enjoy, just barren rock. We'll not be us anymore either of course, time will tell what we evolve into.

[1] https://en.m.wikipedia.org/wiki/Timeline_of_the_far_future

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

#136

Post by brnt »

thaumasiotes wrote: post #125
protoman3000 wrote: post #117

I recently learned about the estimated age of the universe. It’s only 13.8 billion years. So when it says Venus was hospitable for billions of years, let’s say 2 billion years, that amounts already to 14% of all there was and will ever be. What marvel did happen in this time?

> So when it says Venus was hospitable for billions of years, let’s say 2 billion years, that amounts already to 14% of all there was and will ever be. Huh? You're saying the universe is about to end?

I guess he meant that Venus' habitable days will never return.

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

#137

Post by TaylorAlexander »

dimitrios1 wrote: post #131
galaxyLogic wrote: post #99

Earlier quoted context omitted.

> And it could be again... It could. On the other hand Earth could become the next Venus, if climate change runs out of control. No?

No. For one, Earth is much further away. But most importantly, we have no clue if our current carbon levels are any sort of maxima in regards to what the planet can handle. We just have our own little recent industrialized history, and some charts about the past that are, at best, educated guesses. As George Carlin would say, "The planet will shake us off like a bad cold" Climate change is more important for our spec…

I’m curious if you’ve read research on this? “The earth cannot become like Venus” seems like a strong positive statement that should come from research. I genuinely don’t think our innate intuition is enough here, even if it aids in comedic punchlines.

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

#138

Post by montychain »

ramraj07 wrote: post #74
whoisthemachine wrote: post #19

It's interesting that multi-cellular life developed on Earth around the same time these scientists hypothesize Venus would have become uninhabitable. Unrelated... still, fun to think about. https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h...

My working hypothesis is that the galaxy (if not at least the solar system) is teeming with rocks containing Protozoa that are ready to colonise any planet with the right conditions (in a matter of thousands of years after the conditions are right) the moment they are ready. Perfectly explains everything we see and honestly would not be surprising at all. We need to start developing meaningful working hypotheses and…

It's an interesting theory but I feel like it doesn't reflect the reality. If galaxy was indeed teeming with rocks containing some sort of microbes than where did they all come from? It'll take an enormous amount of effort to populate an enormous amount of rocks and scatter them across the galaxy. I wouldn't presume that Protozoa would appear on asteroids just by itself. For this mechanism to work there would have to be millions or even billions of such rocks for every star system to ensure that at least a couple of them land on a ripe planet and some of the microbes survive the impact. Most of these rocks would end up falling into a star or a massive gas giant. And we have to think in terms of billions of years here. So these populated asteroids would have to keep falling on a potential life-supporting planet for a couple billions of years until it indeed become habitable.

Ok, even if this mechanism of fertilizing planets was indeed functional as you suggest, we still don't see any evidence of intelligent life out there in our galaxy. Surely, out of billions of planets and billions of years time there would emerge at least a couple of civilizations capable of colonizing a significant part of our galaxy. There's certainly a slim possibility that we may be the first of such civilizations, but I'd be surprised to find out that humanity is THE smartest and most reasonable civilization out of billions others that our galaxy was capable to produce so far.

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

#139

Post by pb82 »

cookiengineer wrote: post #68
duxup wrote: post #7

Growing up I absorbed all the space stuff I could find. But it wasn't until recently that I realized that the solar system didn't just form into some static natural state where it largely didn't change until say the sun was finished with it's lifespan. Rather it evolves, changes, planets are habitable, then not, moons are formed and break up, even frozen planets are geologically active and are changing, Saturn's ring…

What's mindblowing is the search for planet 9...once you start to realize that we are surrounded by thousands of dead solar systems (brown dwarfs that very likely were red dwarfs before) in our immediate neighborhood. Imagine what we could accomplish by mining their resources!

Brown dwarfs are failed starts, something between a large gas planet and a red dwarf. Red dwarfs don't turn into brown dwarfs when they die. In fact a red dwarf's lifetime is so long (up to trillions of years) that its unlikely that we ever see one dying. It is believed that they turn into white dwarfs when that eventually happens.

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

#140

Post by tim333 »

onion2k wrote: post #129
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.

Wouldn't a solar shield get heated up by a force equal to the amount of energy it's providing shielding for minus whatever it can reflect away? That would require some significant cooling even if the shield is 99 9999% reflective. How would you stop it getting too hot and eventually breaking down?

Nah. It would radiate out heat if it got hot, especially if the back was dark. I don't think the heating would be much worse than putting something out in the midday sun on earth.
Post reply on HN