We All May Have a Little Martian In Us 168
coondoggie writes "Men are supposed to be from Mars as John Gray's iconic relationship book would have you think, but new research presented this week suggests that in reality; we all may hail from the Red Planet. 'The evidence seems to be building that we are actually all Martians; that life started on Mars and came to Earth on a rock. It's lucky that we ended up here nevertheless, as certainly Earth has been the better of the two planets for sustaining life. If our hypothetical Martian ancestors had remained on Mars, there might not have been a story to tell,' Professor Steven Benner of The Westheimer Institute for Science and Technology said."
Re:slow news day (Score:2, Interesting)
Yes, let us never speak of this again, regardless of whatever new evidence is found! Evar!
New evidence? What evidence, new or old?
We haven't even set foot on mars, yet we have had pronouncements that this or that rock found here or there clearly came from mars.
An entire Galaxy ignored, an entire Solar system looked over, Vast Oort Clouds discounted, and a gazillion asteroids hand waved away.
But by god this rock couldn't POSSIBLY been from anywhere but mars!!
Re:slow news day (Score:4, Interesting)
The life we know needs certain things, in particular liquid water. That exists very few places. Mars is proven at this point to have had liquid water in the past, none of the other places has.
On the other hand the force necessary to hurl a chunk of mars off the planet would likely kill even microscopic life in the containing object. I find it silly that people are suggesting that could happen. I imagine that an impact of significant enough magnitude to eject rocks from the surface into space would liquify the rocks (and thus killing everything on them) before they were ejected into space. Even if it didn't liquify them they would be heated to thousands of degrees by the instantaneous change in velocity needed to reach exit velocity. Even if you could come up with some bizarre circumstance that could get life bearing rocks into space the radiation between earth and mars would kill almost anything that wasn't 10's or 100's of feet buried in rock. So eve if it's survives the exit and is buried deep enough to survive the journey what on earth sustains it for the journey? It's not like it would have packed a knapsack. Even with food the temperatures would be near zero and very little life can survive being frozen.
To me what kills the idea is just how impossible the odds are. You have several near impossibilities all combined to move life from one planet to another.
Re:slow news day (Score:4, Interesting)
very little life can survive being frozen
On the contrary, and Samantha Wright please correct me if I'm wrong, but I'd think a whole big hunking lot of single-cellular life can in fact survive being frozen. I mean, come on, human fucking sperm even does. Never mind that frozen life is well, frozen. While the DNA repair mechanisms are dormant, so are the copying mechanisms. Bacteria can live quite deep within porous rocks. I'm not exactly sure if it's really necessary for ejecta to be always heated up to sterilization. Now I'm not saying that this little life-from-Mars theory has got any legs to stand on just yet, but your arguments don't really do much to discount it, I don't think.
Ugh (Score:4, Interesting)
And how are organic molecules going to turn into tar in the presence of ample water and little heat (such as the case on the surface)? He seems to have neglected that high levels of liquid water (yet another oxide, but one which was prevalent in the early Earth environment) also inhibits the formation of tar.
The only argument against water as the tar-inhibitor agent is that it is "corrosive" to RNA. But which of these three compounds (including oxides of boron and molydenum) are currently found in living cells in quantity?
Re:slow news day (Score:4, Interesting)
However, GP's other points remain valid. Not much survives the heat of an impact, even less (molten) debris ejected into space. Simple organic molecules are destroyed easily with heat (and radiation), not even talking about (primitive) life forms.
As for the article, we can safely assume that probability of life originating from Mars is about the same as amino acids from "outer space" hitting the earth - or the remains of FSM's tomato sauce.
In other words, pure fantasy.
Plenty of oxygen (Score:4, Interesting)
Molybdenum doesn't require free molecular oxygen to oxidize. It can steal the oxygen from other sources.
By the way, when did molybdenum become crucial for life? Did the earliest life require it? I would like to see some proof here.
Perclorates (Score:3, Interesting)
Re:Hypothesis (Score:5, Interesting)
7). "Reverse seeding of life, from Earth to Mars, did not happen." This may be easier to support. Earth's gravity well is greater than Mars. However ruling it out will be extremely difficult.
Actually, some astronomers looked at this back in the 1970s, and concluded that at the bacterial level, Earth to Mars travel is fairly easy, and has almost certainly been going on since early in the Solar System's history.
The mistake people are making is thinking that impacts ejecting rocks are the way that bacterial would make such trips. The astronomers examined and verified the effectiveness of an entirely different mechanism. The Earth (and all the planets with atmospheres) has a "cometary tail" produced by the solar wind. This tail is mostly gases, of course, but it also includes a small proportion of dust-like particles. It turns out that this includes bacterial spores, which have been found at all levels of the Earth's atmosphere, and have probably been there for a few billion years.
The Earth's cometary dust tail is thin, but it is of interest to astronomers. Taking pictures through a haze of air and dust is more difficult than avoiding the air and dust, so some astronomers need to keep track of our planet's tail and avoid it when possible.
Anyway, measurements back in the 1970s did show that the Earth's dust tail contains small particles the size of bacterial spores, and since they exist in our upper atmosphere, they are to be expected in the tail. How long they can survive in space isn't well understood, but tests in orbit have shown some rather good survival rates of the spores when exposed to conditions near our planet.
So the solar wind has been pushing small quantities of Earth's air outward for a few billion years, and that includes assorted tiny dust particles and bacterial spores. This has to have "contaminated" all the outer planets with Earth's bacteria for all that time. Whether they've survived anywhere else isn't known, but Mars is the most likely place.
Some of the astronomers have also calculated the spread of our dust tail outside the Solar System. Most of it does escape eventually, and gets lost out in interstellar space. We make an orbit around the galaxy roughly every 220 million years, so since life arose on Earth, we've been spraying the galaxy with our bacterial spores for around 15 to 20 orbits.
How such spores survive out there, nobody knows, of course. But it's an interesting thing to consider when the "panspermia" hypothesis comes up. Any planet that develops bacterial life will, probably within a billion years or so, start spraying them out into the galaxy like we do, possibly contaminating any compatible planet anywhere else in the galaxy over the next few billion years.
(I recently read somewhere an estimate, based on current measurements of the solar system's dust, the likelihood of spores from Earth hitting Earth-size planets around stars at various distances. The numbers were nonzero, but I took them all with a grain of salt -- also included in the dust -- since so little is known about the reality of interstellar space and the likelihood of a spore surviving a trip that may last a few million years.)
Re:slow news day (Score:5, Interesting)
And not that many years ago, the FBI insisted their scientists could tell you if the bullet that killed someone came out of the same box of bullets found in the suspects house, based on a spectral analysis of the lead in the bullet.
They had a whole bunch of scientists willing to swear to this in court under oath.
And it all turned out to be utter and complete bullshit. More than one defendant got out of prison on that one.
You can not know the origin of a random rock from outer space that lands someplace on earth. You can't even tell with certainty where a random rock from earth originated.
Re:slow news day (Score:4, Interesting)
And not that many years ago, the FBI insisted their scientists could tell you if the bullet that killed someone came out of the same box of bullets found in the suspects house, based on a spectral analysis of the lead in the bullet.
Non sequitur. Did anyone claim the lead was not from Earth?
They had a whole bunch of scientists willing to swear to this in court under oath. And it all turned out to be utter and complete bullshit. More than one defendant got out of prison on that one.
Non sequitur. Don't care.
You can not know the origin of a random rock from outer space that lands someplace on earth. You can't even tell with certainty where a random rock from earth originated.
You can't know anything with certainty. So what. They make arguments, and I find theirs compelling whereas I find yours more akin to ignorance mongering.
To clarify, I don't think life originated on Mars. I do think it's reasonable to think that meteorites identified as being from Mars are from there, mainly because of ratios of gases found in the rocks lining up with the composition of the Martian atmosphere (e.g. here [www.imca.cc]). If you don't think that's reasonable then fine, but if I were to bet it wouldn't be your way.
That's about all I have to say it on it. Thanks ;)
Re:Dubious Evidence (Score:5, Interesting)
Its because the organisms being talked about are likely some form of bacteria or similarly simple single celled organism. There are many, many varieties of that kind of life, and there seems to be at least one microorganism that can survive in almost every extreme condition short of raw flame, and I'm not even certain if that would stop them forever.
So, this is how I see it having gone down:
Life evolved on mars as single cellular organisms and those organisms spread all over the planet, including places where it was extremely warm, and places where it was chillingly cold. Some of those hardy organisms started to work their way deeper and deeper into some rocks in an exceptionally frigid part of the planet, where they lived, if not thrived, highly adapated to the cold, to the point where they could survive being frozen during the coldest parts of the martian year.
One day, during one of the several bombardments of the solar system by meteors and comets and whatnot, something struck the martian surface near these organisms hard enough to accelerate the rock they were living in out of mars' gravitational field. Coincidentially, this rock was also large enough that when it would eventually enter earths atmosphere, enough of it would survive that not every little organism in it would be fried from the re-entry heat.
So this rock floats in space and the little organisms in it get frozen. And I mean really frozen. Phillip J. Fry frozen. Because, you know, it's actually cold in space. And this rock drifts around, going who knows where for thousands, millions, maybe even billions of years, until it gets caught in earths gravity well. It falls down the well, hits the atmosphere and the outer layers start burning off, and the rest of it starts to warm up. The little organisms in the center of the rock get thawed out, and when the meteor hits one of the early earths primordial seas, some of these little organisms start to slip out of the micro-fractures that were inflicted on whatever remains of their rock.
Those little organisms find for themselves an environment that is alien, but useable. And they thrive. If not off the bat, then within a few generations thanks to how fast single celled organisms can evolve. At some point we get primordial earths first figurative algae bloom, and suddenly the seas are full of em! They start sucking up the methane and other gasses that were present in the early earths atmosphere, coughing out oxygen, and eventually the oxygen in the atmosphere exceeded the earths capacity to store it in rocks and we started to get an oxygenated atmosphere. The seas turned from green to blue as other gasses were driven out of the oceans and replaced by oxygen, and stuff started evolving until one day we arrive at a discussion where some people can wrap their heads around the plausible, yet highly speculative possibility that maybe life did in fact start on Mars instead of Earth, and other people simply can't handle such an awesome idea.
Re:Dubious Evidence (Score:4, Interesting)
Re:Dubious Evidence (Score:5, Interesting)
Exactly! Whenever I see claims that life started on Mars (or was brought here on meteors) I wonder why there is even a need for those hypotheses. You need pretty strong evidence that life COULDN'T have started on earth to resort to such a much less likely theory...