So it becomes cool again and we can roam, digging around. What traces could we find?
Venus could have been habitable for billions of years (2019)
101–110 of 236 posts
Re: Venus could have been habitable for billions of years (2019)
#102Did some planetary body hit Venus and destroy all life 700 million years ago ? Maybe even changed its rotation the other way ?
Re: Venus could have been habitable for billions of years (2019)
#103Imagine the timeline if humans and our technology were around 700 million years ago, at a time when some of our sibling planets were potentially habitable.
Re: Venus could have been habitable for billions of years (2019)
#104And 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.
> Sure, it may take a millenium, but the sooner we start, the sooner we finish.
For technology with uncertain results and uncertain resource requirements, this does not follow. It may well be that any effort we spend today is entirely wasted 100 years from now.
Re: Venus could have been habitable for billions of years (2019)
#105It'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…
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 produce life." So the chance that life gets to Earth increases multiple fold.
One problem for this theory is that if it takes a thousand years for Earth to get protozoa from another planet, then we would expect to have gotten multiple different types of Protozoa. But there is basically no variety on Earth: it's all carbon, and 99% uses oxygen (a few use sulfur).
Re: Venus could have been habitable for billions of years (2019)
#106Earlier quoted context omitted.
we are terraforming the earth - see how much co2 is being pumped out!
Since we're trying to move _away_ from "terra", should we call the current state maybe "marsforming"?
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.
Re: Venus could have been habitable for billions of years (2019)
#107Earlier quoted context omitted.
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.
The oldest known undisturbed area of the Earth's surface is only about 2 million years old It turns over very fast in geological time https://www.livescience.com/3542-oldest-surface-earth-discov...
And yet we have fossils from half a billion years ago. "Oldest surface" is not a good measure for how long evidence can survive.
Re: Venus could have been habitable for billions of years (2019)
#108And 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.
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Re: Venus could have been habitable for billions of years (2019)
#109Earlier quoted context omitted.
The oldest known undisturbed area of the Earth's surface is only about 2 million years old It turns over very fast in geological time https://www.livescience.com/3542-oldest-surface-earth-discov...
A fair point. I wasn't thinking about tectonic subduction, which would hide pretty much all evidence that anyone was there. Though I think that article is talking more about having the same surface exposed to the air for a long time, without being worn down by weathering or covered in silt. You could have an area covered in dirt or partly eroded away, and still be recognizably an artifact of civilization for a long t…
Have a look at the Silurian Hypothesis. If one can examine things very closely, literally on the ground, then the window of detectability might extend to hundreds of millions of years, even billions perhaps. But from orbit, there's not so much hope of detection after a million years
Re: Venus could have been habitable for billions of years (2019)
#110Earlier quoted context omitted.
Also Venus is closer (minimum 38.2 million kilometer for Venus vs minimum distance of 55.7 million for Mars). However I don't know about the microbes, i fear that they might get killed at an average temperature of 737 K (464 C). https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.htm... https://nssdc.gsfc.nasa.gov/planetary/factsheet/venusfact.ht...
Hopefully someone can provide more info, but apparently there are some bacteria in geothermal vents near Baja California that seem to be able to handle venus-like conditions. No idea what the details are though
Interesting, wikipedia says these microbes are called thermophiles, and that they can survive for up to 122 degrees celcius. That is still less than what they have on Venus, that is 464 degress. https://en.wikipedia.org/wiki/Thermophile