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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."
Lawyers.
They can survive anywhere.
liqbase
Leads to the interesting possibility of xenophilic bacteria and algae impacting Jupiter and having their entry slowed greatly by the thick atmosphere. The deeper it goes, the warmer it gets, and there are bands in Jupiter's atmosphere that are comparable to Earth's atmosphere, past and present.
Might be interesting to one day discover man was far from the first Earth-borne species to begin colonizing other planets in the solar system.
"To pass through the jungle; silence, courtesy, ferocity, as the occasion demands." -- Kamau, "Proper Passage"
How about this:
Named the World's Toughest Bacterium by the Guinness Book of Records, the large red spheres of Deinococcus radiodurans (translation: strange berry that withstands radiation) can not only endure acute radiation doses of up to three million rads but more remarkably, can actually grow when exposed to radiation continuously.
You really don't want to meet this in a dark alley, however with that much radiation, I doubt it would be dark for long.
liqbase
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?
Tartigrades, otherwise known as Water Bears might survive such a journey. They're the cutest microscopic animals ever!
'This must be rather frustrating if you're a bacterium that survived launch from Earth'
On behalf of the League of Sentient One-Celled Organisms, I would like to assure you that it is nowhere near as frustrating as your high-handed, primitive, and anthropomorphic notions of bacterium emotion.
Actually in many of our cultures (and I use that term advisedly), being hurtled through a vacuum and smashing into a rock is considered to be a transcendent spiritual experience, and required as an initiation rite into our shamanic traditions.
Blow that into your Kleenex.
Ooo man the floppy drive is broken. No wait. The computer is just upside down.
At -179C, the bacteria are gonna need parkas.
Take the cheese to sickbay, the doctor should see it as soon as possible - B'Elanna Torres, "Learning Curve"
"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.
Solar Billiards - v1.3.11
Please input the following earth-impactor parameters for your simulation
Impactor diameter (m): 5000
Impactor velocity (m/s): 12000
Ecliptic Declination (deg): 7.3
Please input the following solar system parameters for your simulation
Target diameter (km): 4000
Target solar altitude (AU): 15
System asteroid density (objects/AU^3): 0
Click start to begin
Calculating Trajectories...Done
Results:
Total impacts of earth origin: 107
Impacts of non-earth origin: 0
Congratulations! Impact count greater than 100! Click here to redeem your free iPod!
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.
Well, as long as they had an intel processor with them, they've got plenty of heat to survive.
"Everything worth innovating today will go to court tomorrow."
The fact that we have determined these things hit Earth makes them no more likely to hit Earth. I say we carry on ignoring them like we did before anyone had any clue such a thing could happen.
"The White House is not an intelligence-gathering agency," -- Scott McClellan, Whitehouse spokesman.
As far as life as we know it, there is no evidence that microorganisms could grow at -179C. There is some evidence that hardy spores can survive in extreme conditions (even naked space as is the case for some mold spores that briefly enter the upper atmosphere of Earth and come back down to spread long distance), but I find it difficult to believe that anything could grow and divide at such low temperatures. That seems chemically and thermodynamically impossible with the microorganisms that we know of now. The leaves the possibility of evolution to some type of life we don't know about, but again, evolution requires geological time scales, and the trip from here to Titan, presumably in a dormant state, would not allow sufficient time or for that or the multiple rounds of natural selection. Neat idea none-the-less, but not enough incidents to play the probability game properly.
>chemistry is very different from Earth's.
There are some Earth life forms with some pretty weird chemistry. One example is purple sulphur bacteria. Instead of using water as a reducing agent, they use hydrogen sulfide. This is oxidized to elemental sulphur and sometimes on to sulphuric acid. Heck with this water/oxygen thing. These are a very old group of organisms.Some mornings it's hardly worth chewing through the restraints to get out of bed.
And the decelleration and temperature resulting from the crash landing is substantially different from the acceleration and temperature resulting from an explosion that caused the rock to exceed escape velocity in the first place?
Yep.
Not "the explosion" itself, but the environment felt by the launched rock, which could be lifted relatively gently by the rocks and soil under it, as the atmosphere above it is lifted out of the way / along with it by it and the neighboring material.
It isn't the stuff that gets HIT by the asteroid/comet/whatever that get's launched. It's the stuff on and near the top of the ground nearby that gets lifted by the violence spreading out below it.
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
Steven N. Severinghaus
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....
Laws are horrible moral guides, moral guides make even worse laws.
People are also only pointing out animals we know exist being on those boulders. It's entirely possible there were many more species hundreds of millions of years ago that were as resiliant as the "Water Bear" towards harsh conditions, but suffered some other short coming that lead to their extinction on Earth.
EpiAdv - if you like Pokey the Penguin, try this comic!
(Given that gigantic, green tentacled monsters haven't been stalking NASA bases recently, we can also assume that not only were they not killed off, they did not suffer significant mutation from the radiation. Actually, the study indicated that no obvious mutations had occured of any kind, implying that the DNA was highly resiliant to the effects of ionizing radiation.)
On the basis of Mir and the NASA experiment, it can reasonably be concluded that microbes can survive interplanetary travel, more-or-less intact, at least within the solar system. Deep space is far, far nastier and the present experiments don't show that interstellar microbial travel is possible... but it doesn't rule it out, either.
We believe that microbes can remain in a suspended state for tens of thousands of year (or perhaps millions), on the basis of studies of microbes discovered in ice core samples. It's not easy to rule out contamination, but the experiments seem repeatable. It is possible to imagine that microbes may be present in some geodes. They would certainly be present inside rocks that have fissures caused by flowing water or ice cracking.
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, and the shattering of the rock would be a very useful way for the microbes to be released. In the case of interstellar travel, it would also provide better shielding. Ideally, you'd want rock from the Peak District in the UK - some places have a nice mix of galena (lead ore), calcite and blue feldspar. I could easily imagine a meteorite with such a mix containing microbes in amongst the calcite, and lead casing would improve the odds of surviving the millions - if not billions - of years needed to travel between systems.
(This is not to say this has happened, and I'm sure I'm going to get my wrist slapped by a geologist who will point out all the flaws in my reasoning. However, if in the year 3000 we finally reach Alpha Centauri and find a planetoid with bird flu on it, they'd better damn well name the planetoid after me.)
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Don't forget that the microbes that live in extreme conditions got there by gradual adaptation. There were once a bunch of microorganisms that could survive in a zone 100 yards to 500 yards from a volcanic vent. Some of those were a little hardier, so they could survive 90 yards from the vent, and so on. But move some of those to a tidepool and they will almost certainly die. For Earth bacteria to live on Titan, they must have lived somewhere with conditions at least a little like Titan, close enough that at least one could survive the differences. And differences in environmental chemistry aside, a microbe from Antarctica (coldest temperature -89 degrees celsius, and that's a record, not an average) would have a hard time thriving on Titan at around 90 degrees colder. Not impossible, but I'd feel safe betting the family fortune against it.
Some see the vessel as half full; others see it as half-empty; We pour it out on the floor and laugh
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.
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