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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."
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
Tartigrades, otherwise known as Water Bears might survive such a journey. They're the cutest microscopic animals ever!
It looks like Earth's pecker tracks could be all over the solar system. What if Europa had an atmosphere early in it's life? Was it always relatively airless? So even if we discover life elsewhere in the solar system, there's a good chance it'll resemble Earth's. Even if Europa was airless what about this scenario? Big Earth rock hits Europa, vaporizes millions of tons of ice and creates a temporary atmosphere. Then a second rock hits Europa in this brief interlude. It could have survived. Unlikely, but possible.
"You'll get nothing, and you'll like it!"
I mean, if we ever got there and searched for native life forms, these findings would just add another factor of uncertainty. Say we send up robots or even taikonauts (probably won't be astronauts any way), and they really do find DNA/RNA-based life (except lawyers, as someone else suggested). How would one tell a archaebacterium which hitch-hiked the vessel from an archaebacterium that hitch-hiked an asteroid boulder from a bacterium that has been created there?
The grass is always greener on the other side of the light cone.
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
(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)
Deliberately contaminating the environments of our neighboring celestial objects with our mutagenic biomatter might be considered an unfriendly greeting by the local populations.
But we'll keep doing it anyway. It seems unlikely that human spacefaring will be found in the long term to be a significant vector for the spread of life -- not because we don't do it but because life has been littering the solar system for much longer than we've been exploring it.
In addition to the rocks that smote the dinosaurs which might have spread life to other planets there are:
The better question is not "does life exist elsewhere?" but rather "if not, why?" We just have to probe around as best we can to get some preliminary results on the first question before we explore the second.
The question I want answered involves the asteroids -- who will be the 49'er to figure out how to capitalize on that unimaginable wealth? The investment is significant, but if you could get a reasonable amount of water, a nuclear power plant and about 50 people to the asteroids, in thirty years you could own everything outside the moon's orbit. Of course at that point closing the deal on the rest of _everything_ would be trivial.
Help stamp out iliturcy.
So the theory is that meteors hit the earth, and this somehow kicked up *boulders* to fucking *leave the atmosphere*? Think about how much force it takes to push things we *want* to go out of the atmosphere? And the escape velocities involved.
Is it just me, or does the idea of meteors kicking stuff *off the earth* not pass the laugh test?
Rank my idea: http://www.sinceslicedbread.com/node/531
Well, don't lawyers require other lifeforms to suck from?
So if Titan was lifeless, the lawyers would die. If not, well then poor Titanians.
urd
You might be interested in D. radiodurans which can survive 1.5 million rads whereas 500 - 1,000 rads can kill a human. However this item explains the repair mechanism.
Bitter and proud of it.