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Life On Mars: ALH84001
Celestius writes "This press release from NASA Ames states that 'An international team of researchers has discovered compelling evidence that the magnetite crystals in the martian meteorite ALH84001 are of biological origin,' and moreover that these crystals are not only older than any previously known form of life, but were also definitely formed before the meteor fell to Earth. Skeptics remain, of course, as quoted in this article from today's Chronicle, but suffice to say, NASA seems pretty confident." There's also a report on the BBC as well.
Unless we invent a time machine this won't be a problem.
Where in the article were you led to believe that there is CURRENTLY life on Mars?
Or perhaps it was a different article than I read.
The one I read indicated the rock was 3.9 billion years old.
What are the chances that an extraterrestrial bacteria could wipe out our civilization?
About as close to zero as anything can get. Seriously, humans can't even share diseases with most other mammals. You think we'll make good hosts for something that hasn't even evolved on the same planet? I doubt these things would even survive in our hot, wet, dense atmosphere. Chances are that these things never adapted to infect any host of any kind, since they were probably the most complex life on Mars. And as if that wasn't enough to protect us, life on Mars is almost certainly very long dead.
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The full text is Here on everything2, but for those you who don't like to click, I will exerpt the most important part:
Dr James Lovelock was first to articulate the reasons why Mars is barren. Put simply, let us look at the only example that we have of a world where life exists: Earth. How could we devise a subtle test to determine the existence of life on earth's surface? We don't need to; it sticks out a million miles away. Green continents. Atmospheric composition.
Life radiates to all available niches, it diversifies, it takes over, it envelops and transforms. Life doesn't just keep a foothold on a planet. If it is present at all, expect it to be almost everywhere on or near the surface. Expect entire geological phenomena such as coal and chalk to be caused by living things. Expect the planetary atmosphere to have puzzling components, like 21% highly reactive oxygen and traces of methane.
Sure, earthly life would have a tough time just keeping a foothold on Mars. But with Martian life, we would even expect like to not arise at all unless it did so in a form suitable to the prevalent conditions, and be further honed by hundreds of millions of years of adaptation.
It is likely that the concept of a planet having traces of life is not a valid one: there will be diversity and many filled niches, or nothing. Even if there are or were a few bacteria on mars, then it's not what we think of as life: there is no ecology, no biosphere, no diversity.
Looking for life on Mars is like the old story of the drunk looking for his keys under the lamppost because there's more light there. We look for life on Mars because it's nearby, not because it is a good place to look.
My Karma: ran over your Dogma
StrawberryFrog
For those that can't be bothered to read the articles, at least check out the pics. This could be really huge. The arguments will surely go on until more blatant evidence comes out, but this looks pretty solid - magnetotactic bacteria leave pretty distinctive, if small and fragile, artifacts, and the stuff buried in these rocks sure look like it.
The NASA guys have been studying the artifacts since 1996, and they are now convinced enough to put their reputation on the line. These aren't people to do that lightly.
"That old saw about the early bird just goes to show that the worm should have stayed in bed."
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Earth and Mars have been transferring tons of bacteria-laden rocks to one another for millions of years. This means that each planet has already been exposed to the other's bacterial life. At any rate, Mars's soil is full of peroxides. Between that and the high UV flux, there's not much likelihood of Earth bacteria surviving.
InstaPundit! Ahead of the Curve Since 30 Minutes Ago
I just can't believe what passes for journalism these days:
"Scientists have published what they claim is conclusive evidence that bacteria once lived on Mars.... But some British experts are sceptical, saying the study falls short of absolute proof.... One thing is for certain, though. The crystals, regardless of origin, are agreed to have been a major factor in plummeting CD sales over the past year, and may have single handedly caused the recording industry wordwide losses of over a billion dollars."
Just uncalled for. Truly sloppy journalism. Fact checkers?
Perhaps NASA should try crashing some more shit into Mars. We sure could use some more meteors to look at. This time, though, they could just leave out all of the expensive electronics and save some money! :o}
forth ?love if honk then
I think the discoveries and new possibilities that arise from exploration vastly outweigh any fear of destroying an ecosphere.
Imagine those (or similar) words coming out of Christopher Columbus's mouth, and then think back to your 16th-19th century American history...
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BACKNEXTFINISHCANCEL
The great irony of the War of the Worlds is that the precise opposite of the conclusion to that great tale could occur if we visit Mars - Earthly microrganisms could leak into the Martian environment and cause havoc.
I think the discoveries and new possibilities that arise from exploration vastly outweigh any fear of destroying an ecosphere.
I'm not saying we shouldn't be extremely careful, but what exactly would we gain by not visiting Mars? The preservation of micro-organisms that we will never meet, which may after trillions of years form a civilization that we will never know?
There are always good and bad side effects from exploration... but it is man's natural tendency to explore.
So you must ask yourself this one question... do you want NASA and related scientists to be the first to explore Mars, or some unregulated (perhaps largely unscientific) group of people?
One or the other of those two groups will get to Mars first.
-thomas
"And like that
However, is this the responsible thing to do? Wherever man travels he brings with him a shower of varied microrganisms, which adapt to local conditions. It would be extremely difficult to rid any travelling ship or astronaut of the organisms. If they got free in the Martian environment, they could wreak havoc.
The great irony of the War of the Worlds is that the precise opposite of the conclusion to that great tale could occur if we visit Mars - Earthly microrganisms could leak into the Martian environment and cause havoc.
Although this is unlikely, extremely unlikely in fact, even assuming that life exists on Mars now, the chance is not one we should take. I do not support a manned mission to Mars in the light of this discovery - this is rational because although the chances are so very small, we would be risking a lot - an entire ecosphere.
You know exactly what to do-
Your kiss, your fingers on my thigh-
You know exactly what to do-
Your kiss, your fingers on my thigh-
I think of little else but you.
Bullshit. Just because our galaxy has a certain configuration doesn't mean that's the only configuration that can support life. Do you honestly think that life can only occur in the uncharted backwaters of the unfasionable end of the western spiral arm of a particular type of galaxy?
>The star has to be exacly the right size nad exactly the right point in its life
Bullshit. Our sun is about 4.5 billion years old. Life has existed on Earth for better than 3 billion years of that. So the sun has been at "exactly the right point in its life" for 2/3 of its life. Uhmm, right. As for size, the only thing that matters is the luminous intensity at the planet's surface. A larger or brighter star simply requires a larger orbit, thicker atmosphere, or more temperature-tolerant life.
>The planet has to be composed of exactly the right material...
Bullshit. Earth is mostly iron and nickel. The crust is mostly silicon, aluminum, and oxygen. Only one of these elements is important for the basics of life. To produce Earth-like life, the planet needs certain amounts of carbon, hydrogen, nitrogen, oxygen, phosphorus, etc. at the surface. These do not have to be the primary constituents of the planet.
>...be the right size...
Bullshit. Earth-like life requires a certain minumum size, to hold an atmosphere. There is really no definite upper limit on size, though. Life, especially simple life like bacteria, would have absolutely no trouble evolving on a planet 10 times as massive as Earth.
>and be at exactly the right distance from the sun
Bullshit. Again, Earth-like life requires the surface temperature to be within a certain range, but it's hardly exact. The primary requirements are that water be a liquid and proteins hold together against thermal disruption. Known life on Earth exists in temperatures over a range of better than 350 Kelvins. Even if you needed a smaller temperature range, you have 3 variables to adjust. Sun brightness, orbit distance, and atmosphereic reflectiveness. It's not too hard to find a combination of those that will produce the right temperature.
>There has to be a moon at exactly the right distance and exactly the right size
Bullshit. Whose ass did you pull this statement out of? Do you honestly expect me to believe that chemical reactions on Earth's surface are dependant on the luminosity and gravitational pull of the Moon?! At least the other arguments sounded credible before you thought about them. This one's just ridiculous.
>...this is not a troll...
Sure had me fooled.
Bugrit! Millenium hand and shrimp!
Some of the magnetite and pyrrhotite in the Allen Hills meteorite was found in or very close to calcium carbonate globules with surface textures consistent with partial dissolution. While magnetite (Fe3O4) and pyrrhotite (FeS) can be inorganically precipitated under reducing conditions (high pH), these conditions stabilize carbonate.
It is possible that the iron sulfides were created at high pH and then the pH was lowered and the carbonates were partially dissolved; however, under such conditions the pyrrhotite and magnetite would also exhibit some kind of weathering, which is not evident in the samples.
Bacteria, however, are known to exhibit intracellular coprecipitation of iron sulfides and magnetite and extracellular coprecipitation of the same in anaerobic conditions.
See J.L. Kirschvink, A.T. Maine, H. Vali, Science 275, 1629 (1997) for more information.
I don't know if the crystal chains reported today were found in close proximity to carbonate globules, but they came from the same meteorite.
All of the various findings that indicate possible life in ALH84001, from polycyclic aromatic hydrocarbons, to magnetite crystals to the so-called microfossils have possible non-biogenic origins.
The real question is what is more likely -- that a bunch of (generally) incompatible inorganic processes all occurred at approximately the same time and place, or that ancient martian life [of which we have no hard evidence at all] is responsible.
At some point Occam's Razor points to life; I am not sure we are there yet, but every new study of ALH80041 seems to push the balance a little bit further in favor of ancient life on Mars.
That means that the chances of wierd sex with some alien chick with 3 breasts just got so much better.
:)
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