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Earth Life Possibly Could Reach Titan
dylanduck writes "New simulations show that big asteroid impacts on Earth could have sent about 600 million boulders flying into space. About 100 have reached Jupiter's moon Europa - but they landed at 24 miles/sec. 'This must be rather frustrating if you're a bacterium that survived launch from Earth,' says a researcher. But 30 boulders from each impact reach Titan - and they land gently." From the article: "'I thought the Titan result was really surprising - how many would get there and how slowly they'd land,' Treiman told New Scientist. 'The thing I don't know about is if there are any bugs on Earth that would be happy living on Titan.' Titan's surface temperature is a very cold -179C and its chemistry is very different from Earth's."
Bacteria survived several years on the lens cap of a camera left on the moon. It's resilient stuff!
Does this sig remind you of Agatha Christie?
"The whole thing was a simulated what-if, something made abundantly clear from start to finish. They "Know" these impacts happened and at precisely what speed because IT WAS A FEKKING SIMULATION, DAMN IT!"
This is true, but also stated in the article "The cause of such impacts would be comets or asteroids between 10 and 50 kilometres wide, Gladman told New Scientist: "The kind of thing that killed the dinosaurs."" meaning that these numbers were not just pulled out of an orifice but rather based on actual historical earth impacts. Is it proof that these rocks made it to Titan (and in the numbers estimated)? No. But it is probable. The last line of the article sums it up nicely; "Gladman agrees that life may be unlikely to survive once on Titan. But he says major impacts may have happened "tens of times" throughout Earth's history and that these could have sent Earth rocks to other solar system bodies. "I just set out to answer this question: is it possible to get something there?" he says. "The answer is yes."". Draw your conclusions from there.
Beware of he who would deny you access to information, for in his heart he dreams himself your master.
Tough bugs, sure, but traveling through space also means withstanding the full bore radation of Mr. Sun, with no atmosphere to protect you. I'm not sure I want to meet one of these in a dark alley.
You probably already have. There are bacteria that can survive and even grow exposed to levels of radioactivity found in some parts of nuclear reactors. It looks like some of these bacteria also live in the human stomach.
The thing is, harsh environments and to things like drying out can cause DNA damage, and the same incredible repair mechanisms that help some species to survive those allow them to survive intense radiation.
Incidentally, bacteria surviving to reach Titan is not that interesting - far more exciting is the possibility of them reaching another moon of Saturn - Enceladus, which probably has liquid water.
Addressing two points. The reason Mars meteorites can be identified as such is because of the ratios of the elements found within them... they differ from the rest of the meteorites, AND match Mars. Every major rocky body in the solar system has such a unique "signature".
As for surviving hard radiation... we already know of microbes that did it for years when later Apollo crews found them from the exposed exteriors of equipment left behind by the earlier crews. One you stress a microbe into a "spore" state, it's really hard to kill them.
Steven N. Severinghaus
There is certainly a broad layer where the pressure and temperature are roughly Earthlike. However, there is nowhere in Jupiter's atmosphere where the composition is more than vaguely similar to Earth's primal (prebiotic) atmosphere, and nowhere similar to Earth's current atmosphere at all. There is effectively no free oxygen in Jupiter's atmosphere, and only tiny traces of anything other than hydrogen and helium. Most of the traces are simple alkanes and water.
When all you have is a hammer, everything looks like a skull.
Ribosomes. If they are the same, or similar to one of the few types in earth-life, then it is almost impossible that they came from elsewhere. If they are different....
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Howdy,
.NET and marketing crap. I develope .NET for a living, and 95% of what is out there IS marketing crap.
Can some mod who has extra points please mod parent up. He got slammed on his first post by one down mod. Thanks to the wisdom of the powers that be, and their wonderful algorithms, he is now qualified to post at 0 for the rest of his existence.
Look at the post that caused the problem. He asked about
No reason for this guy to have been down modded. No reason for him to be in the 0 realm. If you want to mod this offtopic too, great. I left my karma bonus on so you could take an extra swipe at me.
Thanks,
Have a nice day.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
Once you're talking of microbes on the inside of rock, then impact velocities would be much less important. The rock would absorb much of the impact
Actually, microbes are so tough that there is little need to absorb impact stresses. Some experiments have involved bacteria put inside a rifle bullet and fired at rock (to see if they could survive the decelerations of a meteor impact). The bacteria survived and could reproduce.
This is why there is little need, as this article suggests, to have the rocks containing bacteria travelling slowly.
Totally... I've even seen a clip where scientists have exposed some bacterium to radiation, so to scramble their DNA... Some bacteria can survive, actually repair DNA that was very signifigantly damaged, and then go on about their normal lifecycle. The little bastards are tough!
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No, because helium is a noble gas, and as such chemically inert. The reason oxygen is so usefull is that it is very highly reactive; while it is certainly possible for an organism to inhale helium and not be harmed by it - indeed, even a human can survive that - it won't do it any good either.
Waters role is as a small-moleculed polarized liquid. Since water molecules are polarized, there's a strong attractive force between them, giving water very usefull properties - surface tension, high boiling point, etc.
What, didn't you get the memo ?-)
I suppose it would be possible to build life from anything that can form complex enough structures, but would we recognize it as life is another matter.
Forget magic. Any technology distinguishable from divine power is insufficiently advanced.
Oxygen is the simplest substance around that has those characteristics.
But couldn't life evolve to, say, breathe helium and drink alkaline, for instance?
Definitely no on the first one. Helium has no chemical properties whatsoever. Hydrogen isn't a good candidate either, since H2 is a reducer rather than an oxidizer. I would imagine that a cell that relied on an outside reducer would need to have free oxidizers sitting around inside itself. It would probably rip itself apart.
Drinking alkaline is more reasonable, depending on the concentration.
I don't know if there's a rule that says, "Anything in the universe that's alive has to breathe (carbon dioxide|oxygen), drink water, be carbon-based, etc."
The "carbon requirement" is simply this: only carbon can form large, stable, complex molecules. Sulfur and nitrogen can form polymers, but not complex ones. Silicon can form large complex molecules, but they tend to fall apart because of the availability of d-orbitals.
Human being (n.): A genetically human, genetically distinct, functioning organism.