Perhaps this will be a short debate, perhaps not, but here goes…
Is it possible that life and intelligence evolved on Venus (or conversely Mars) millions of years ago, flourished, and then became extinct (or decided to leave the planet due to massive changes in the atmosphere for example.)?
If so, would there be any way for us to find out? This assumes there have been millions of years between the extinction and our own evolution.
Is it possible that humanity (intelligence based) evolved millions of years earlier, then through some catastrophe, became extinct? For example, (I know I’ll get reamed for this, but…) Clive Cussler wrote a book called “Atlantis Found” (I think that was the title) which suggested that a vastly intelligent populace existed many thousands of years ago but they were destroyed by a comet (or something).
Now I realize that there would be plenty of evidence out there to disprove an intelligent civilization existed ten’s of thousands of years ago, but what about millions? I realize we’ve found dinosaur bones that are millions of years old, but surely we haven’t found anywhere near the representative population of dinosaurs that existed. In other words, perhaps intelligent life existed but we just haven’t dug deep enough to find it.
Are any of these random assertions possible? What do the dopers think? Is this even worth debating?
Sure. It bears on the question of the prevalence of life in the Universe, which to my mind is a damned interesting question. Seeing as we have discovered microbial life in the volcanic flumes of the ocean floor, I think that bolsters the case.
A lot of folks like to think that life is so rare and fragile, requiring virtually perfect conditions, that its presence on Earth may be unique, even miraculous. Even precisely miraculous.
I take the opposite, I suspect the Big Empty is crawling with life. We shall see.
That’s exactly the point. According to history a meteor smashes into Earth every couple of million years (cite: see that great documentary…shoot, I forget the name, but it is a six part series with Sam Neil doing the narration…wonderful stuff). If a meteor hit Venus (or conversly Earth) ten million years ago, cleansed the planet of all life and traces of civilization, what does that mean to our current society? Would it impact religion? Our purpose here? Go forth and multiply takes on a new meaning if civilization is smited every million years or so. As such, if we ever found evidence of a past advanced civilization (once again either or Earth or Mars) how does that impact our current society?
It has been argued before that such a revelation wouldn’t mean anything to anyone aside from the isn’t that neat factor and perhaps a religious factor among the devote literalists.
Anything is possible. Maybe dinosaurs’ ghosts live today at the Earth’s core where they protect the planet from satan, but there is no data to suggest this. There is no data to suggest that there were civilizations on Mars or Venus or Mesozoic Earth either. Without data these are, as you say, “random” assertions.
If there was ever life/civilisation on venus, it’s pretty unlikely that there would be any trace of it there now - I think I’m right in saying that the surface of venus is constantly being reworked by a combination of volcanic and atmospheric actions. Of course if some kind of life arose that actually enjoys that kind of environment, it may still be there now…
Perhaps right now there are Venusians debating the existence of life on Earth on the local equivalent of a message board there…
Life on Earth? Are you kidding? - look at all that water, and Oxygen too - Oxygen! - floating free in the thin insubstantial atmosphere - Oxygen binds to readily to all sorts of other life-giving chemistries - Oxygen and water [shudder] can you imagine a more hostile environment? - even the probe we sent never made it to the surface.
The Martian rocks in question did not have fossils as such, but formations that could be interpreted as being of organic origin. The minority opinion was that such formations could only have been a result of organic action, i.e. bacteria. However, there are enough indications that such formations ,might have been formed by chemical processes to keep the majority skeptical.
Damn shame, too, far as I’m concerned. I am definitely a Bug Eyed Monster aficianado.
IIRC, the current theory is that since there doesn’t appear to be any volcanic activity on Venus or plate techtonics, the entire crust of the planet flips itself. So, if life evolved before the most recent flipping of the crust, we’d be unlikely to ever find evidence. However, if life developed after the most recent flip, we might be able to detect it, if we don’t wipe it out terraforming the planet to make it habitable for us.
If evidence on Venus was found that life once existed there, I don’t think that most people would be unhinged by it. Many people would no doubt find a way to incorporate into their religions. For example, I can imagine people saying that Venus is the site of the Garden of Eden, and it’s current state is caused by the Fall of Man. Or that the inhabitants were a Sodom/Gomorrah-type of society and were wiped out by God (or the Gods) for being evil. I can even imagine some claiming that it’s evidence of Hell or demons.
As for what that evidence might be, I dunno. Venus is a corrosive environment heated to something like 900°F, so it’s doubtful any metals would survive in such shape as to be identifiable as a Venusian made object (though the locations of those lumps of metals might lead us in that direction). Glass and ceramics, however, I think would be able to survive those conditions. One has to wonder what the world would make of vases found on Venus with Chinese characters on them.
I’m afraid I’m going to have to say there’s absolutely no way there was any life on Venus 5 million years ago, certainly no way there was any civilization. I’ll put in the caveat that this is assuming current scientific results hold up, but that’s just to be formal.
We have a good radar map of Venus. While Venusian SUVs might have been melted down by high temperatures and/or destroyed by sulfuric acid, the roads and structures probably wouldn’t be completely destroyed. A city might get half-melted, but then it’d look like a half-melted city.
In fact, unless we assume the atmosphere has changed radically since life might have existed there, the sulfuric acid wouldn’t do much to the putative SUVs since it’d presumably be in equilibrium with the surface and everything in it (more or less). Furthermore (my wife is kibitzing… ), the sulfuric acid on Venus doesn’t make it down to the surface, instead vaporizing and staying in the middle atmosphere, like rain not quite making it to the desert floor. The temperature is the main problem, and either we have to believe that life existed at the high surface temperatures (or in the atmosphere, a Saganesque idea), or that the atmosphere radically changed in a very short geological time.
Changing the atmosphere on a planet like Venus would be a monumental effort, not simply the result of an impact. There was some widespread acid rain after the Chixculub/KT impact, but the amount is still somewhat controversial, and the effect was probably mostly due to the impactor hitting a limestone target. Even at that, the atmosphere eventually returned to normal. The heat input needed to raise an atmosphere as thick as Venus’ from Earth’s temperature to the current temperature, and keep it that hot for millions of years is simply enormous. Off the top of my head, I’d guess that the necessary energy input would simply destroy Venus.
There is some evidence that Venus underwent a massive volcanic event (or set of events) 500 million years (or so) ago, which covered practically the whole planet in fresh lavas. Last I was keeping track (my old officemate did his dissertation on this stuff, but we graduated about 5 years ago), the cause was poorly understood, but might be due to the lack of plate tectonics on Venus keeping its heat in until it catastrophically comes out.
Now, that could be your sci-fi plot setup-- a hypothetical planet whose scientists realize they’re in trouble because of an impending event like that.
Mars is still controversial. The group that announced the microfossil findings are still convinced they’re right, the skeptics are still skeptical, and it’s unclear how many more tests can be done on those rocks to convince anyone. The people who believe there are microfossils in the rocks seem to be in the minority. We’ve got a lot more Mars data in the intervening years, but we’re still trying to reach a consensus on the other paths to figuring the life on Mars thing out. Again, though, a civilization would almost certainly leave large-scale traces that we just don’t see.