Scientists Study Trajectories of Life-Bearing Earth Meteorites

Hugh Pickens writes "About 65 million years ago, Earth was struck by an asteroid some 10 km in diameter with a mass of well over a trillion tonnes that created megatsunamis, global wildfires ignited by giant clouds of superheated ash, and the mass extinction of land-based life on Earth. Now astrobiologists have begun to study a less well known consequence: the ejection of billions of tons of life-bearing rocks and water into space that has made its way not just to other planets but other solar systems as well. Calculations by Tetsuya Hara and his colleagues at Kyoto Sangyo University in Japan show that a surprisingly large amount of life-bearing material ended up not on the Moon and Mars, as might be expected, but the Jovian moon Europa and the Saturnian moon Enceladus also received tons of life-bearing rock from earth. Even more amazingly, calculations suggest that most Earth ejecta ended up in interstellar space and some has probably already arrived at Earth-like exoplanets orbiting other stars. Hara estimates that about a thousand Earth-rocks from this event would have made the trip to Gliese 581, a red dwarf some 20 light years away that is thought to have a super-Earth orbiting at the edge of the habitable zone, taking about a million years to reach its destination. Of course, nobody knows if microbes can survive that kind of journey or even the shorter trips to Europa and Enceladus. But Hara says that if microbes can survive that kind of journey, they ought to flourish on a super-Earth in the habitable zone (PDF). 'If we consider the possibility that the fragmented ejecta (smaller than 1cm) are accreted to comets and other icy bodies, then buried fertile material could make the interstellar journey throughout the Galaxy,' writes Hara. 'Under these circumstances fragments could continue the interstellar journey and Earth origin meteorites could be transferred to Gl 581 system. If we take it as viable, we should consider the panspermia theories more seriously.'"

Comments

Don't you mean...

[Anonymous Coward]

Godeorites? They were created 6000 years ago along with the Dinosaurs.

Re:Don't you mean...

[Anonymous Coward]

Just once I'd like to see an origin-of-life article on Slashdot without atheists dragging religion into the discussion.

Re:Don't you mean...

[Anonymous Coward]

Oh, come on.... that was quick and moderalty ammusing.

Panspermia

[The Evil Atheist]

If we take it is viable, we should consider the panspermia theories more seriously.

Only as a possible answer to the origin of Earth's life. It still doesn't answer the origin of life itself, wherever it may have started.

Re:Panspermia

[olsmeister]

No, but it could answer the question of how life managed to arise here on earth in a relatively short period of time, and would also exponentially expand the potential area we consider when we think about places that could have been suitable, both chemically and environmentally.

Re:Panspermia

[Anonymous Coward]

I think God did it as stated in the Bible, but since time is relative to Gods perspective and it didn't say there were NO dinosaurs. I guess he just threw a rock to see what would happen at some point. Probably wasn't necessary to mans salvation to give all the details.
Makes more sense than some hokum about panspermia. If a rock hit, no one knew which way the ejecta blew and with such great distances and so many degrees of freedom to take, it is sooooo doubtful it made it anywhere immediately useful to seed anything anywhere or even travelled to some distant system and then land somewhere useful there.
Must be kinda like throwing a handful of marbles over the edge of the Grand Canyon and hoping one lands in someones water-glass somewhere below, maybe.

Re:Panspermia

[fatphil]

I've seen arguments on a scientific mailing list in the last few days that this paper is based on false assumptions. It has assumed (too high) values for masses based on (too low) values for velocities based on the assuption that the meteorites are aiming at earth under its gravity, rather than aiming for the sun under its gravity and accidentally hitting earth on its way towards the sun.

If you change the masses downwards to what they should be, then the chance of them getting through an atmosphere without breaking/burning up and denaturing all its alleged payload become minuscule.

Re:Panspermia

[jellomizer]

God? (Ducks!)

I still follow the premise that Life originated on earth. As a random chemical reaction, that created simple DNA strains that that happened in an area where the environment stayed constant enough for those chemical reactions to persist but changing enough to allow the strain to change over time. The Chemical Reaction that didn't break down allowed for more chemicals to connect to the DNA strand and multiply.

Re:Panspermia

[socialleech]

You should read about the Miller-Urey experiment.

For those to lazy to read about it, scientists have created all of the amino acids required by life, using nothing but inorganic compounds, by recreating the atmospheric conditions of early Earth.

Life may or may not have originated on Earth, but we tested it and found that it could have. If it could have been created here, using nothing but the things that the universe placed here, why couldn't it have also developed else where? Are we the seeding planet of the galaxy/universe? Were we seeded? Or is life just incredibly common?

Re:Panspermia

[Anonymous Coward]

No way was God an onanist. That's a sin you know: "tossing rocks" and "ejecta-ing" your "panspermia" all over the ground.

Re:Panspermia

[ArcherB]

God? (Ducks!)

I still follow the premise that Life originated on earth. As a random chemical reaction, that created simple DNA strains that that happened in an area where the environment stayed constant enough for those chemical reactions to persist but changing enough to allow the strain to change over time. The Chemical Reaction that didn't break down allowed for more chemicals to connect to the DNA strand and multiply.

While thinking about it, the environment would not necessarily need to change to force the DNA to change (evolve). All the "environment" needs is to be stable enough to foster replication. The edges of such an area would provide the change in conditions needed for evolution to take hold. The bonds that were able to multiply at the edges and beyond did so. Those that were not able to didn't.

An example would be ocean vents. This environment is rather stable and fosters life within it. Along the edges, where the conditions are not as favorable to the original life forms, most those that are venturing out will die. Those that don't die continue to reproduce, each surviving generation better able to survive further away from the vents until the need for the vents completely disappears.

Just my $0.02 and I'm not a biologist. But I have stayed in a Holiday Inn and the concepts are not that hard to grasp.

Re:Panspermia

[mcgrew]

From what I've read (which was a LONG time ago so further discoveries and theories may have developed), Earth had little or no oxygen when life developed, and the oxygen would have been a poisonous byproduct, like methane is to today's life.

So life itself would have changed the environment, of course along with other such variables as volcanos, continental drifting, and meteors.

Re:Panspermia

[kanweg]

When you throw a dice, your first throw may be a six. Why are you trying to do statistics with a single event?

Bert

Re:Panspermia

[Migraineman]

I guess he just threw a rock to see what would happen at some point.

So your version of God isn't all-knowing and all-powerful? I'm not buying that a God who is capable of creating billions of planets, stars, and systems wouldn't have a firm grasp on probability and interstellar trajectories. Maybe we should consider that your God is bored (he does control everything, right?) and has set up the universe as a giant Rube Goldberg machine for His entertainment. He would have to accede to non-interference for the exercise to have any value.

Re:Panspermia

[Ashenkase]

I think God did it as stated in the Bible

If its stated in a book of fiction then it HAS to be true.

Excuse me while I go out back to feed my Unicorn.

Re:Panspermia

[Anonymous Coward]

You're not still dragging out that tired old experiment, are you? Have you figured out how many orders of magnitude (both in terms of probability and complexity) bare amino acids are away from the simplest self-replicating thing we have found on earth so far? You'll need a lot more experimental evidence than just Miller-Urey to bridge the gap between inorganic compounds and life.

(Yes, there are experiments that show self-replication of specially-designed ad hoc molecules, but the experimenters have to provide all the raw materials in just the right amounts for those experiments to work. Not exactly realistic pre-biotic conditions.)

Re:Panspermia

[SQLGuru]

When you throw a dice, your first throw may be a six. Why are you trying to do statistics with a single event?

"God does not play dice with the universe."

Re:Panspermia

[Anonymous Coward]

When you throw a dice, your first throw may be a six. Why are you trying to do statistics with a single event?

"God does not play dice with the universe."

Well not since his GMPC got one-shotted by the Romans anyway.

Re:Panspermia

[CSMoran]

When you throw a dice, your first throw may be a six. Why are you trying to do statistics with a single event?

Bert

Not statistics. Educated guesses. With just one throw available to reason from, the educated guess for the next throw is another six.

Re:Panspermia

[Anonymous Coward]

The best part about that experiment is how he traps the amino acids because he knew they'd be destroyed if they were to continue through the cycle. I think atmospheric conditions of early Earth were not so kind as to trap amino acids simply because they would have just been destroyed right away.

Re:Panspermia

[thechemic]

This article sheds new light on how the amino acids would not have been destroyed right away. http://www.newscientist.com/article/dn14966-volcanic-lightning-may-have-sparked-life-on-earth.html

Re:Panspermia

[paleo2002]

When comparing panspermia to a terrestrial origin for life people seem not to fully comprehend one important factor: time.

It began raining on the Earth about 4-4.4 billion years ago, meaning surface temperatures and atmospheric conditions were stable enough for the oceans to accumulate. Some of the earliest evidence of biochemical alteration of the atmosphere (banded iron formations) first appear about 3.7 billion years ago. That's over 500 million years for naturally occurring amino acids to jump to self-replication and then to simple prokaryotes. Now, think about the rate at which microorganisms reproduce. 500Ma is about as much time as its taken for life to jump from single-celled forms to modern vertebrates, etc.

Panspermia includes too many unknown and slim chances. And, as mentioned elsewhere in these posts, where are these life-seeding bolides coming from?

Re:Panspermia

[symbolset]

where are these life-seeding bolides coming from?

Did you know that all of the elements on Earth heavier than iron were once inside a star? It's true - and not our star, either.

Re:Panspermia

[Anonymous Coward]

Yes but they haven't created the life itself.

Build a rocket is one thing. Landing safely on the Moon is another. Getting back alive... even harder still.

Re:Panspermia

[ColdWetDog]

Amino acids don't self replicate. That's what DNA (or RNA) is for. However, your primary point is still valid. Time allows nature to futz around until something works. 500 million years is a long time. A very long time.

Re:Panspermia

[Chris Burke]

Of course Miller-Urey is pretty irrelevant now that we've found amino acids floating in clouds in space. They're everywhere.

Anyway, so we're accepting that spontaneous assembly of self-replicating molecules is possible in principle, but appealing to the low probability of the right conditions appearing. Well, billions of years of constant change due to geologic activity and countless deep-ocean vents of varying compositions, plus the fact that we're here, suggests that while the probability may be low, the expected value of the experiment over that time frame is not so low.

Re:Panspermia

[Chris Burke]

God? (Ducks!)

Indeed -- not God, but Ducks! Some might say they're one in the same (especially the ducks). And given ducks' well-known sexual proclivities, a theory of panspermia where basically every object in the galactic vicinity, even those with no chance of the payload taking root, being "inseminated", makes a lot of sense.

Re:Panspermia

[CSMoran]

where are these life-seeding bolides coming from?

Did you know that all of the elements on Earth heavier than iron were once inside a star? It's true - and not our star, either.

Except for the ones we created by nuclear fusion.

Re:Panspermia

[Intrepid imaginaut]

All the "environment" needs is to be stable enough to foster replication.

Its the bit between "dumb chemicals" and "things actually replicating" where we're a bit wobbly. If a stable environment were all it took we could have recreated the process many times.

Re:Panspermia

[MozeeToby]

How many orders of magnitude? Ok, let's say that the odds of those amino acids forming a self replicating 'thing' are 1000000000000 less likely than the formation of the amino acids themselves. It took Miller-Urem 1 gallon of water and 1 week of time to produce virtual every amino acid required for life. Now instead of a gallon, you have the entire surface area of the Earth's oceans at the time. And instead of a week you have millions, if necessary billions of years. Every time someone talks about how bad the odds are for evolution or abiogenesis, I have to wonder if they are really thinking about what they're saying. Yes, the odds are going to be long. Very, very long. But so is the scale, both in size and time.

Re:Panspermia

[geekoid]

Other planets.

You can have both.
Hell, Human beings could be wiped out by a giant piece of rock from a destroy planed, and organic compound on that rock could eventually become the new life forms.

Re:Panspermia

[geekoid]

No it isn't. It shows that amino acids can come from inorganic compounds. Being on Earth isn't needed.

Re:Panspermia

[Barbara, not Barbie]

If we take it is viable, we should consider the panspermia theories more seriously.

Only as a possible answer to the origin of Earth's life. It still doesn't answer the origin of life itself, wherever it may have started.

So you mean mom was right - you are evil alien spawn?

Re:Panspermia

[Electricity Likes Me]

Also any chemist knows that you always get a little of an unlikely reaction product if your original volume is big enough, or you mix things for long enough. You only need to make a self-replicator (or just a vaguely catalytic) product once.

Re:Panspermia

[tinkerton]

I'll offer a view that goes the other way round, that of the irrelevance of panspermia. Life originated on earth because under the right conditions that is inevitable. Incoming meteorites with life or predecessors of life wouldn't have made any difference. Life on other planets is hard. Incoming seeds originating from earth wouldn't make any difference.

If you look at the origins of panspermia theories however, they're of the silly kind: "life is very difficult to start so it must have come from elsewhere".

Re:Panspermia

[cusco]

I'm left assuming you have a couple hundred million years to let your experiment run, then? Good grief, I can set up a wireless mesh network and let it run and connectivity will be perfect for years until that moment that a train is going past, the janitor is running the vacuum with the bad motor brushes, and a tractor-trailer rig is parked in the fire lane simultaneously. If you wait long enough pretty much anything combination of things that CAN happen WILL happen, good or bad. The Urey-Miller experiment produced amino acids after only a few days, what if they had been able to expand the experiment and let it run for a few decades?

Re:Panspermia

[Anonymous Coward]

Except for the ones we created by nuclear fusion.

Everything up to iron is created by the normal fusion going on in any given star. Everything heavier than iron, up to uranium either had to be created during a supernova, or less probably, moments after the big bang. Arguably, these materials come from stars, and it is still fusion which does the work.

Re:Panspermia

[Anonymous Coward]

Mod parent up. This has to be the sanest rationalisation of an all-powerful deity bestowing freewill I've ever heard.

Still, the concept of my life being nothing but entertainment is slightly creepy. Maybe it's pinball, and we're just some nasty bacterial infection?

Re:Panspermia

[tinkerton]

all of the elements on Earth heavier than iron were once inside a star?

Heavier than iron? don't recall exactly, but I thought our star wasn't in the stage yet where it was producing carbon. Is it making a lot of lithium yet? And now that I think of it, possibly a lot of our hydrogen has been part of a star as well.
I think everything heavier than iron was made in a supernova.

Re:Panspermia

[cusco]

I've seen several recent articles speculating on below-ground sites as being possible locations for abiogenesis. Some clays form a convenient 'scaffold' for amino acids to line up, and also happen to promote the creation of lipid bubbles. Energy sources are abundant and varied underground, and chemicals migrate only slowly, giving time for multiple reactions to happen. Also, the sheer volume means innumerable possible appropriate locations.

Re:Panspermia

[tomthegeek]

Nice try, global warming believer!

Re:Panspermia

[tinkerton]

I think God started the world 6000 years ago, but the only way to get everything looking right so that it looked much older, was to run a full simulation of the whole history of the universe beforehand and then switch to the real thing, like switching between a virtual machine and a physical computer. All in His Head of course. You can't put a few dinosaur bones in the ground and withstand deeper and deeper scrutiny, now and with the technology of 1000 years from now, without ever failing. Not unless you just run the complete simulated history first.

Re:Panspermia

[Chris Burke]

No it isn't. It shows that amino acids can come from inorganic compounds. Being on Earth isn't needed.

Sorry, what are you saying? We've discovered amino acids all over the place in space. The experiment showing that amino acids can arise naturally is thus largely redundant with the direct observation of naturally occurring amino acids.

Re:Panspermia

[P-niiice]

A rock did hit(you seem doubtful), because there's a huge crater. Given the size and shape of the crater, you most definitely can get a good idea of the size, speed and angle of the meteor and from that you can determine if stuff flew into space. You can even perform experiments to simulate it.

Re:Panspermia

[Eivind Eklund]

It wouldn't have been DNA; DNA is too complicated and has problems replicating without a bunch of machinery. RNA is one possibility, though I personally have the feel that it is too complicated as well. One example of a hypothesed simpler pathway is Cairn-Smith's Clay hypothesis (http://en.wikipedia.org/wiki/Abiogenesis#Clay_hypothesis) though experiments indicate that clay crystals likely aren't stable enough to work for this purpose. However, there only needs to be some kind of material with the right properties, and then evolution rapidly creates variation and more advanced structures. (For more on abiogenesis, you may want to see the nice talk.origins FAQ at http://www.talkorigins.org/faqs/abioprob/originoflife.html)

Re:Panspermia

[Anonymous Coward]

Sounds great but engineers have created all the nails and screws, hammers and drills, drywall and 2x4s and plywood required by modern homes but these pieces have yet to assemble into a livable dwelling with no outside help. But hey, maybe if you put them in a pile and let it sit in a chamber with the atmospheric conditions of early Earth for billions of years, you will eventually get a house out of it.

"Life may or may not have originated on Earth, but we tested it and found that it could have" except in the context of this testing, all we can really say is that we have not proven anything because life was not manufactured during these tests.

Re:Panspermia

[CSMoran]

Sorry, but I'm not following your reasoning.

When the boffins created several atoms of dubnium in a lab in Dubna fifty years ago, were these atoms ever inside star?

Re:Panspermia

[Eponymous Hero]

a rube goldberg holographic TheSims: Universe, complete with sploits, hacks, cheaters and buggy code. in other words: perfect.

Re:Panspermia

[Anonymous Coward]

The most and best evidence for the origin of life remains design. Who did it, when, how, and so on is a separate matter. But, if we are going to take seriously the hypotheses that (a) life originated naturalistically on earth (2) life originated naturalistically somewhere else, and traveled here via a meteorite, we should also be able to accept the hypothesis that life was designed.

Heck, Craig Venter's lab might design life that makes it to a distant planet to seed life there!

Re:Panspermia

[Thuktun]

I think everything heavier than iron was made in a supernova.

Very briefly inside a star, then, for generous values of "inside".

Re:Panspermia

[tinkerton]

Fine with me. But why start at Iron? The only element on earth that hasn't necessarily been inside a star before is hydrogen. Forget about the lithium btw, that was a mixup. Anyway, I'm not sure the sun is making carbon without looking that up, but certainly nothing above it.

Re:Panspermia

[Anonymous Coward]

Who are you to tell God what to do?

Re:Panspermia

[tinkerton]

Cool, someone modded this insightful. Well actually the switch from simulation to reality happened 10 minutes ago. Setting up all the brains with all the memories was one of the easier challenges.
No wait, it did happen 6000 years ago. The switch suddenly made people responsible for their actions, gave them free will and stuff. Yeah, that should be it.

Re:Panspermia

[tinkerton]

If it talks like a God, walks like a God and looks like a God it's a Duck?

Re:Panspermia

[Intrepid imaginaut]

Amino acids mean nothing. I'm not saying it was intelligent agency or anything, but I am saying that we haven't clue one what happened. We have, in short, no evidence that it CAN happen. This "hundreds of millions of years" line is just another god of the gaps. Science!

Re:Panspermia

[Anonymous Coward]

There are no odds for abiogenesis or for evolution or other lines of thought. The thing people tend to forget about odds and chances is that the odds and chances are directly related to information which the observer believes. For example, the odds of the Miller-Urem experiment producing these different amino acids would probably be said to be zero by many people before the experiment while others perhaps would just give an honest "I dont know" and yet others would say the chances were very high. It turns out there were no odds at all, only missing information - the "chances" of producing the results that it did were in reality 100%.

So the numbers work out like this:
either abiogenesis happened or it did not - one of them is absolutely 100% true, whether you have observed it or not
either evolution is true or it is not - again, not based on whether someone even ever had the thought
So for both, the "chances" or "odds" are not 50/50 they are 100% but the question for the observer is which one (did / didnt happen - true / not true) and the point of these types of experiments is to aid the observer in coming to an understanding as to which it might have been

Funny that then - if "the odds of those amino acids forming a self replicating 'thing' are 1000000000000 less likely than the formation of the amino acids themselves" and you have billions of years and a global ocean you still wind up with - either life came about that way - or it didnt - one of these is 100% correct with no odds or chances necessary. The only question, then, is which one was it? Ultimately, we weren't there to observe life's beginning and so it has become a matter of faith for some (on all sides), and a matter of question for others (the "I dont know"s)

Re:Panspermia

[Anonymous Coward]

If God ran the simulation in His head, it would be a perfectly accurate simulation down to the smallest subatomic particle. All the animals would behave exactly as real animals, including the humanoid ancestors... it would be indistinguishable from "reality." So why "switch over" to reality 6000 years ago? How do you know "reality" isn't still God's atomically accurate simulation? How could you tell the difference?
(I'm going to invoke Poe's Law because I am not sure if you're serious or joking, but it doesn't matter. I've run this exact same thought experiment scenario myself more than once.)

Re:Panspermia

[symbolset]

Dubnium was reportedly first discovered in 1968 at the Joint Institute for Nuclear Research at Dubna (then in the Soviet Union). Researchers there bombarded an americium-243 target with neon-22 ions.

The americium-243 was almost certainly formed inside of a star, so... yes. Heavier than iron elements are typically formed in supernovae fusion processes. They may be created in nuclear fusion bombs or experiments also, but not in your specifically referenced experiment - which involved fission.

Re:Panspermia

[jc42]

When you throw a dice, your first throw may be a six. Why are you trying to do statistics with a single event?

Except that, as far as the main topic goes, there were in effect billions and billions of "events". True, the impact itself was one event (or maybe a small number of events, if the asteroid broke up before impact). But for the "panspermia" topic, the result was a cloud of chunks of rock, each with its own trajectory. So a large number of projectiles were tossed randomly into the solar system, and some of them into the galaxy at large. Each one amounts to a separate attempt to infect some other planet somewhere with a sample of material from our planet.

One of the interesting observations from the (very few) deep-drilling projects has been that there are bacteria-like living organisms as far down as we've managed to drill. The evidence is that the Earth's entire crust is a mass of life-bearing rocks. When the K/T impact happened, there were almost certainly just as many tiny living critters in the rock then, most of which would have transformed to spores as soon as their warm, comfortable home cooled too much. The ejected rocks that were big enough to shield the spores from radiation have been expanding in a cloud since then. Well, OK; many have already impacted something in the solar system. And, as the article describes, a subset has reached other solar systems, and impacted something there.

This was much more than a single "event", as far as the resulting rock cloud is concerned. It was (and probably still is) a massive natural "experiment" as infecting the rest of the galaxy with whatever life from Earth can survive the trip.

Of course, we don't know that the chances of survival are zero or higher.

In any case, some astronomers were writing of this scenario back in the 1970s. And they didn't have much evidence then, either, except that they could calculate roughly the rate that ejecta from Earth and the contents of Earth's "dust tail" have been escaping to the outside galaxy. This is just the latest in a sequence of such articles over the past few decades.

Re:Panspermia

[KhazadDum]

Amino acids mean nothing.

Well, there you have it folks. Forming the building blocks of proteins means nothing.

Re:Panspermia

[Thuktun]

I didn't write it, but perhaps you missed the "and not our star, either" bit.

Re:Panspermia

[Intrepid imaginaut]

Forming self replicating DNA and RNA from base chemicals means something. Amino acids are seeded throughout nebulae, so yes they mean nothing.

Re:Panspermia

[CSMoran]

The americium-243 was almost certainly formed inside of a star, so... yes

I do not care much about the americum-243 in here, it's an isotope of a different element. I'm using the example of dubnium as an element whose atoms were never created in a star, but rather on Earth, by fusion from americum-243 and neon-22 -- a counterexample to the proposition "all of the elements on Earth heavier than iron were once inside a star" which I disagreed with. The origin of the element americum is not relevant here.

Re:Panspermia

[styrotech]

Something about pan-dimensional beings (aka mice) comes to mind.

Re:Panspermia

[Anonymous Coward]

And it's made of wood.

Re:Panspermia

[gregor-e]

The panspermia hypothesis doesn't take into account the inherent instability of DNA or the extremely hostile nature of space. The only way life stays alive is by constantly repairing itself. That requires a living ecology, with food, water and all the other good things that life needs. Ejecta thrown out into space won't have those good things for long. So that requires that all the DNA-bearing particles be dormant, like bacterial spores. Thing is, near a lethal-radiation source like our sun, DNA doesn't stand a chance. After a few weeks of normal radiation, enough DNA damage will be done to render these spores unviable. If the sun throws a tantrum, even 5 minutes of exposure can do enough damage to be lethal to living things that are actively trying to repair their DNA. Dormant spores would be reduced to odd molecular fragments that a seasoned xenochemist might say came from life at one time. Panspermia just doesn't hold water in our solar milieu.

Re:Panspermia

[dwye]

And he runs it in the debugger, and miracles are changing the variables while running in single-step mode. Yeah, that works.

Bishop Berkeley 1, Atheists 0.

By someone's scoring, at least.

Re:Panspermia

[dwye]

So THIS explains why the only birds to survive the K-T Event were (drum roll) ducks. Or at least duck-like. Look it up.

Re:Panspermia

[dwye]

Most hydrogen, helium, and lithium were created in the Big Bang. After lithium there is a problem making beryllium (I think because it breaks down too easily at the temperatures and densities when atomic nuclei became stable) and so all of that and heavier nuclei were produced in stars. Heavier than iron is only created during a supernova, and I expect that a lot of isotopes lighter than iron were created then, as well. Since the Sun is a Population II star, that would actually be several successive supernovae.

Of course, what our star is producing in its fusion is almost immaterial, until to swells up to red giant phase and starts out-gassing heavily. And we will be gone, by then.

Re:Panspermia

[guspasho]

Relatively short period of time compared to what? We literally have no idea what we're talking about, so how can anyone say whether the time in which life appeared was short or not?

Pan-spermia theories always annoyed me because they seem to violate Occam's Razor and only manage to pass the buck. How did life start on earth? It didn't, it came here from somewhere else!

Re:Panspermia

[dwye]

Also, high concentrations. The level of biochemicals in the pre-biotic seas were supposedly about the same as in a bowl of chicken soup. Imagine a billion bowls of sterilized chicken soup sitting around for 100 million years or two. Things will happen.

Re:Panspermia

[dwye]

No, because someone could say that the amino acids in clouds were created by God or The Gods (as opposed to created by laws and initial conditions created by the patron God Of Biochemistry), or alternately point out that the concentration in galactic clouds are too low, and that the amino acids would probably break up in the heat of initial planetary formation, ignoring any planetoid strikes like supposedly produced the Moon.

Miller-Urey produces biochemicals at whatever level one needs (about the level of chicken soup, supposedly), whenever you need, until life starts playing games with atmospheric chemistry.

Re:Panspermia

[Unoriginal_Nickname]

"Not only does God play dice, but he sometimes throws them where they cannot be seen."

Re:Panspermia

[Artifakt]

The Urey-Miller experiment and its many variants were widely misinterpreted, and your "What If" is precisely where everyone who abused the results went off the tracks. You've thrown out what looks like an innocent rhetorical question and is actually an ontological boobytrap on a par with "Can God make a rock so big He can't lift it" or "Which Springfield do the Simpsons live in?".

To explain: When Urey-Miller was first announced, thousands of people confidently announced what they thought would happen if you expanded the experiment and let it run. Time-Life predicted we would produce true living organisms from scratch within a year. The Government of the USSR claimed it would prove there was no God within six months and that U-M would lead to the overthrow of the entire west and be historically seen as the final nail in the coffin of capitalism within a decade. IBM gave a million dollar grant to some students just to develop the one shot specialty computer they thought would be needed to run the experiment on a life producing level (and this was when a million was real money). Practically every living PHD certified Biologist of the time went out on a limb and asked your what if, and then made a prediction that was totally wrong, in cold print, in reputable magazines such as the New Yorker, National Geographic, Science, and Smithsonian. People who liked the "God of the Gaps" argument siezed on the claim that U-M was its prime example, and that Urey and Miller had proved scientifically there was no God. in doing this they insisted the argument be phrased to include that science was constantly creating true progress and the gaps were getting smaller. When it was pointed out that overall, U-M had not made the gaps smaller*, the American Athiests association tried to get a number of educators fired for saying that, suffered three suicides, and refused to rephrase a word of its articles on the subject for the next 25 years. Are you sure you want to ask that, of all questions? It seems sort of like innocently asking what's in that pert, little, gift wrapped box, with the yards long, slimy green tentacle sticking out of it.

*Urey himself pointed out that they had shown it was far easier to get from a primordial soup to amino acids than anyone expected, but that the experiment also showed it was much, much harder to get from those amino acids to proteins than was thought at the same time. That's basically saying that Urey-Miller had not made any 'gaps' any smaller on average, so if your God of the Gaps argument includes that the gaps are shrinking so there is less and less that needs God as an explanation, the U-M experiment is a lousy argument for your position.

Re:Panspermia

[Anonymous Coward]

It's true, dust doesn't kick much stuff off of the Earth's surface. But, the object considered was of a known size and velocity.

What is being stated is that this ONE event that we know happened, would have 'seeded' bacteria on almost every planet in our own solar system, and would by one Million years afterwords, have seeded several nearby solar systems also.

This isn't a new idea. it has been brought up repeatedly since the 1960's. The bacteria, molds and algae involved have been shown to survive in space, under various conditions. Spores can exist for a great many years, and under very low temperatures can exist in a viable state for extreemly long periods of time.

It's time to stop the desperate objections and consider the evidence.

Yes, it is possible.

Re:Panspermia

[Anonymous Coward]

So you're saying global warming is a good thing?

*ducks

Re:Panspermia

[marcosdumay]

The Urey-Miller experiment didn't just create amino acids and RNA basis. It also linked those elements at random in chains where shorter chains were way more common than long ones. That means, expand the sample size and the experiment time and it is quite possible that something like us come from it.

Re:Panspermia

[symbolset]

The americum was. Improving it to dubnium doesn't change the history most of those protons had in the heart of a star. If you've an example for Chlorine fused into Irridium that might be a counter to my initial statement. But you don't because outside of certain types of supernovae, it does not happen.

Re:Panspermia

[tinkerton]

Not really joking. Let's call it "ironic emulation". The interesting/frustrating bit is that you've got the guy doing the thinking all set up to conclude that since the simulation is nearly equivalent to the real thing, why should he bother about the difference. But then he wiggles out again by introducing free will/guilt/responsibility. The more general question is how an intelligent inquisitive person can continue to believe in creationism.

Re:Panspermia

[CSMoran]

It was not improved to dubnium, for fsck's sake, just like seven is not an improved five, after you add two to it, it's a different number. Addition of protons means getting a different element, that's the essence of the definition of chemical element. The original statement concerned "all elements". And it was wrong -- dubnium is an example of an element that was never created in a star, even though the constituent protons may have a history of having been in a star. Were we just adding neutrons, it would have been a different story (and the same element).

Re:Panspermia

[tinkerton]

Nice, I didn't know Poe's law. My interpretation of Poe's law would probably be more friendly that most though. Or less friendly to the guys in the role of the superior intellect.

Re:Panspermia

[The Evil Atheist]

*Urey himself pointed out that they had shown it was far easier to get from a primordial soup to amino acids than anyone expected, but that the experiment also showed it was much, much harder to get from those amino acids to proteins than was thought at the same time. That's basically saying that Urey-Miller had not made any 'gaps' any smaller on average, so if your God of the Gaps argument includes that the gaps are shrinking so there is less and less that needs God as an explanation, the U-M experiment is a lousy argument for your position.

I would posit that getting from nothing to amino acids is a much more critical discovery. While going from amino acids to proteins may be harder, in terms of explanatory power, it is simply more important to show that amino acids can form from common compounds. Without that step proven, any abiogenesis theory is pointless.
It is very possible that it takes different conditions from the Urey-Miller experiment to create proteins from amino acids.

Re:Panspermia

[Chris Burke]

No, because someone could say that the amino acids in clouds were created by God or The Gods

They could also say the results of Miller-Urey are the result of God. :P

They could -- and have -- also said that since Miller-Urey was an experiment performed by humans it is still a sign that a creator is needed, its similarity to hypothetical natural processes notwithstanding.

Convincing Creationists is not the goal here. Which is good, because it's futile.

alternately point out that the concentration in galactic clouds are too low, and that the amino acids would probably break up in the heat of initial planetary formation, ignoring any planetoid strikes like supposedly produced the Moon.

The point isn't that nebulae are the source of amino acids on earth. The point is that amino acids are a common organic molecule that appears in a variety of natural locations in space. The point is that finding amino acids forming naturally in the absence of biological processes is quite possible, even normal.

Re:Panspermia

[FreedomFirstThenPeac]

Without Loss Of Generality ... assume life appeared spontaneously on Earth. The theorem is proven the same way regardless of this generalization.

Re:Panspermia

[Anonymous Coward]

"God does not play dice with the universe."

Albert Einstein everyone.. give him a hand..

Re:Panspermia

[RockDoctor]

A rock did hit(you seem doubtful), because there's a huge crater.
...
You can even perform experiments to simulate it.

Boring!

Let's perform experiments by throwing 10-km diameter asteroids at our own planet. What could possibly go wrong?

and all galactic life will be like star trek

[alen]

humanoids walking on two feet with funny heads

Re:and all galactic life will be like star trek

[geekoid]

There are a lot of advantages to being bipedal. On planets with land.

Re:and all galactic life will be like star trek

[CubicleZombie]

humanoids walking on two feet with funny heads

And hot chicks with blue skin.

Re:and all galactic life will be like star trek

[Kahlandad]

There are likewise many, many disadvantages to being bipedal, which is why it has not become commonly seen outside of dinosaurs (and their avian ancestors) and primates.

Re:and all galactic life will be like star trek

[mcgrew]

We still haven't found extraforgostic life.

that's depressing

[circletimessquare]

so the culmination of mankind's civilization, scientific efforts, and technological achievements, is to go to some exoplanet, only to find some foot fungus some dinosaur had long before mankind ever appeared?

Re:that's depressing

[Anonymous Coward]

It could be worse, the dinosaur foot fungus may have evolved further than us ...
well for most people it would be worse since they don't see a need to improve on current state of affairs,
I for one welcome out dinosaur foot fungus overlords!

Re:that's depressing

[Anonymous Coward]

so the culmination of mankind's civilization, scientific efforts, and technological achievements, is to go to some exoplanet, only to find some foot fungus some dinosaur had long before mankind ever appeared?

... where it then evolved further and began teaching creationism in classrooms.

Re:that's depressing

[Anonymous Coward]

Minor point I have to make when I see this sentiment: there no such thing as 'evolved further' when you're not talking about direct descendents. Evolution isn't working towards something\anything, no single trait is 'more evolved' than another, just better suited to its environment.

Place Bets Here

[flyneye]

Hmmm, made it to other Earth-like planets instead of randomly catching a closer strong gravitational field or drifting randomly into nothingness.
Even making Europa would be kind of like hitting a cockroach with a needle from across a football stadium.
Oh to be the house, if this scientist ever landed in Vegas with a wallet-load... Sounds like someone needs to re-fill the ol' grant jar.

Re:Place Bets Here

[19thNervousBreakdown]

Apparently you've forgotten about gravity.

Re:Place Bets Here

[jochem_m]

and the fact that it's more like hitting any of a dozen cockroaches with a million needles...

Re:Place Bets Here

[Anonymous Coward]

Yeah, Europa is orbiting something with lots and lots of gravity.

Re:Place Bets Here

[Anonymous Coward]

hitting a cockroach with a needle from across a football stadium.

Tebow could do it! Oh wait. I mean he could hit a needle with a football stadium from across a cockroach (as long as the needle didn't move.)

Re:Place Bets Here

[Chris Burke]

Even making Europa would be kind of like hitting a cockroach with a needle from across a football stadium.

True. Now explode a pile of trillions of needles and see if any one of them hit the cockroach.

Oh to be the house, if this scientist ever landed in Vegas with a wallet-load...

If the bet was that any of the visitors to Vegas would win the slot machine jackpot, the house might not be as willing to make the wager as you.

Of course they'd only make that decision after doing what this scientist did, and actually calculating the expected pay-out. Estimating probabilities by gut feel isn't going to make you a winner in Vegas, even if you are the house.

Re:Place Bets Here

[foamrat]

Now that's funny, I don't care who you are.

Re:Place Bets Here

[flyneye]

Which gravity? The Suns? Are you assuming the ejecta came out in a general direction available to magically put it under the weak gravitational field of planets and moons so distant it would be like trying to get a BB to stick to a magnet by throwing it across the stadium? Did you not take into account how many directions are available that do not line up with the motions of our Suns hub of planets and asteroids? If it went in an upwards direction relative to our position around the sun, even nearby gravity would steer it only a bit as it flew at amazing speeds through the vacuum to nowhere in particular. Reach a distant system from there? Did you win the Mega-millions jackpot? No? Probably just some organic space crap floating somewhere to this day.
It's probably nicer to think of it in the role that this story imagines it, just not very likely. I just can't make myself see it. I'll see it when I believe it or visa versa, whatever.

Re:Place Bets Here

[Anonymous Coward]

No doubt your assesment of the odds is correct.... ...which by no means disproves the theory one iota.

Re:Place Bets Here

[flyneye]

To add to my Vegas theme, consider the planets are moving like a roulette wheel. Further consider that gravity could also act as a slingshot rather than a mitt, dependent on distance from the modifying source it approaches. The numbers of the odds just roll like cherries, bells and bars on a slot machine, the more criteria you add.

Re:Place Bets Here

[flyneye]

I dunno about a trillion. Let's add that to the mix though.
If it were that means the ejecta really splattered like Gallaghers melon in a lot of directions, but also that smaller amounts went with each "packet". perhaps a few "needles"were icy raindrops and hit. Then you face odds of survival. How's earthlife going to do as an ice chunk of earth water or frozen mudball on the surface of an icy moon? Of course the odds of these raindrops (which are still dispersing further from each other, the further they travel in this splatter scenario. This makes the odds of further planets getting a survivable amount of "geo- sperm" less than Europas.
        Even then we must consider the many directions it could go. We're not too far from the edge of the Milky- Way, did it go toward or away? Even up or down from that perspective are options. Then let's not forget gravity. This stuff could be flying around space in chunks or pieces to this day and not land anywhere.

Re:Place Bets Here

[Electricity Likes Me]

You do realize the solar system is not necessarily aligning its orbital plane with the galactic orbital plane, and that the volume of the galaxy around it's orbital plane is enormous?

Something going "up" isn't heading out of the galaxy necessarily. In fact, unless it achieves galactic escape velocity, or falls into a conduit of unusual gravity interactions, then it's going to be orbit in and be captured by something, somewhere, eventually.

Re:Place Bets Here

[flyneye]

And it makes some speculation amongst geeks on a forum kind of a fun thing.
Kind of like an impromptu open-source peer review. We could call it a beer review if that would make you more happy and less troll-y , Mr. Grumpy pants.

Re:Place Bets Here

[onyxruby]

More like hitting a cockroach with a needle from across a football stadium, and you have millions of needles being launched at speeds well high enough to leave orbit. And then every so often you fire your needle cannon again and again.

To put this in perspective, all you have to do is look at the moon. The chances of any given spot on the moon being hit by an impact are incredibly small, so small they are astronomical. However when you look at the moon, you can see the entire thing is covered with impact craters. Your proverbial needle is being fired at your proverbial cockroach in large quantities, again and again. Sooner or later your cockroach /is/ going to get hit by a needle, a second needle and so on.

It also helps that their are what you could conceptually think of as gravity highways in space. Now you've discovered that your needles aren't just firing across the stadium randomly, but that the cannon is at least firing in their general direction.

http://www.popsci.com/military-aviation-amp-space/article/2009-09/scientists-map-out-gravitational-space-highways

Re:Place Bets Here

[flyneye]

Then how many degrees of direction did stuff go, how did it disperse the further it got, how much useful material will fall in a useful place at what stage of development and potential for survival of the place then to find the time needed and then to have potential to rise above any other "geo- sperm" from " competing" sources. The more I think about this the more I get like Hawking about contacting aliens. There are just so many things that seem to work against this, I'm not seeing odds I can live with yet.
Good point, BTW.

Re:Place Bets Here

[Anonymous Coward]

Yep. Then add time. Those odds get a whole lot shorter.

Re:Place Bets Here

[flyneye]

O.K. this has come up in this thread and this is a better example of the space highway thing. Thank you.
This spins the odds back down to something a bit more in grasp, but the viability/distance/dillution thing vs. finding a suitable planet in a suitable age of development is still giving me pause. Although the enormity of time does help a bit.
Good one.
I wish slashdot would implement a feature where we could explode any parent and its children so the group could see the conversation and we could bounce ideas off each other. That would've helped my intent with this, as the Vegas theme seems to be going nowhere.

Re:Place Bets Here

[flyneye]

Yeah, time seems to help but , I'm still considering the viability problems of a viable amount making it to a viable place during a suitable phase in its development barring competition from other more readily suited "geo-spermatozoa" and considering the amount of time it took to develop here, has it developed there.

Damn we need a reply to group option or the ability to explode a particular parent so a group can bounce ideas off each other for more efficient discussion.

Re:Place Bets Here

[cusco]

You need to read up on the dynamics of space flight, and take a look at the sheer volume of material ejected. You are aware that there are quite a number of rocks from Mars and the Moon here on Earth, aren't you?

Re:Place Bets Here

[cusco]

Even up or down from that perspective are options.

Your ignorance of the topic is showing. "From that perspective" there is no up/down, there are only vectors of travel. You should probably shut up now before you embarrass yourself even worse.

Re:Place Bets Here

[onyxruby]

I don't think you were trolling, which I think some of the other posters may have assumed. In essence, I'm conceding your point that for any given piece of debris to make it to a given location is absurdly low, even by astronomical standards. Certainly the odds are so bad that the bet probably would not be legal is Las Vegas.

The thing that makes this paper viable though is that I don't have one piece of debris or just one shot. A large impact like the one that wiped out the dinosaurs could make millions of pieces of debris large enough to survive entry. Repeat this enough times over the years, take into account natural gravity paths between objects and /some/ of those pieces are going to make it to other planets. Give enough time and some of those pieces will even make it to other solar systems.

The meat of the matter is calculating all the "x's" and "y's" that make up the equations. Think of it as being similar to the Drake equation. The more we learn about things like the popularity of planets in other solar systems, the better we can place a value on the given "x" or "y" that is used to come up with the answer.

Or to use your gambling scenario in Las Vegas. Chances are really good for any given bet (piece of debris) that it's going to lose and that the house will win. Certainly in the long run the house is the consistently safer bet to put your money on.

That being said, if you have enough gamblers (pieces of debris) gambling enough times (another piece of debris) eventually someone will win a jackpot (bacteria survives re-entry). How big that jackpot is (bacteria can live and reproduce on another planetary body) and whether or not it become headline producing (bacteria evolves into intelligent life) are entirely up to conjecture. The logic is scientifically sound, the only question is what are the odds, and that is what the scientific paper was trying to address.

Re:Place Bets Here

[AlamedaStone]

Now that's funny, I don't care who you are.

What's a Tebow? (*seizes your nerd credentials*)

Re:Place Bets Here

[flyneye]

I'm thinking of all that and considering the sheer volume of null targets and trajectories that are more likely even in the face of gravity if you consider the wide splatter trajectory. Then there's the other thought that there might be an ejection of something a bit more chunky and less dispersed and what could keep it from finding a chance trajectory that would take it to a viable planet and still be able to make it to evolved life in this amount of time.
Not sure how well rocks evolve or if they hold enough potential to make the dif, What amount of material would be feasable in what environment and the chances for finding that environment.
I can't deny that bits from here end up there and visa versa, But I'm beginning to see success in this being equal in odds to having a viable million dollars land on ME! lol.

Re:Place Bets Here

[flyneye]

For the purpose of discussion we adopt a model not unlike a desktop globe.
I have no purpose for embarrassment as helpful toward any end.
When you can discern metaphors in conversation perhaps you will have advanced to state in which you can make worthy contributions.
        To criticize without enriching the conversation is like dating a model so you can beat off in the closet.

Re:Place Bets Here

[flyneye]

Give this man a cigar!
That brings us closer to fruition than any post yet.
I still have reservations about timeline and possibility of reaching somewhere that bacteria could eventually work up to legs and cable television, but now I would at least drop a small bet on the table, just in case.

Re:Place Bets Here

[flyneye]

It could be too that most usually take my cynicism for trolling, but I am fairly jolly today and it has some bearing.

I still think the /. system could benefit from including some advanced thread abilities to facilitate group oriented discussion in a round table style. Checking messages doesn't always show whats going on elsewhere in the thread.

Sub 1cm Ejecta

[RivenAleem]

How do objects this size survive the trip through the destination planet's atmosphere?

Re:Sub 1cm Ejecta

[dryriver]

The probably answer is that they don't. If things falling into earth's atmosphere (e.g. small meteorites) burn up nearly completely during the trip, then the same should happen to those 1cm Ejecta falling into another planet's atmosphere, no?

Re:Sub 1cm Ejecta

[Anonymous Coward]

How do objects this size survive the trip through the destination planet's atmosphere?

If we consider the possibility that the fragmented ejecta (smaller than 1cm) are accreted to comets and other icy bodies

They're banking on them not being sub 1cm ejecta by the time they arrive at the destination planet. the question then is what acctually are the odds of them coalescing like that?

Re:Sub 1cm Ejecta

[ciderbrew]

I think you have to go into the billion billion range of odds and think up the scenario that allows that 1cm bit to land with its cargo intact. It landed on a still forming plant that didn't have much atmosphere at the time? Is a billion billion enough for this?

Re:Sub 1cm Ejecta

[RivenAleem]

Well, I also considered that, but what happens when a 1cm object is attached to a bigger one, which then enters another planet's atmosphere? It would be the first thing that ablates off, or would be near the surface when it hits the ground at supersonic speeds. Either way, living things on small things have no realistic chance of making it down to the surface alive.

Re:Sub 1cm Ejecta

[Ashenkase]

Your assuming the destination exo-planet has a similar atmosphere to earth. The density of Earth's atmosphere has changed over the course of 4 billion years mainly due to the presence of life. If an exo-planet has little to no life on it pre-ejecta impact then its possible its atmosphere is extremely thin which would allow the ejecta to "mostly" survive its fall down the gravity well.

Re:Sub 1cm Ejecta

[Ashenkase]

It would be the first thing that ablates off, or would be near the surface when it hits the ground at supersonic speeds.

Meteorites large enough to make it through earth's atmosphere hit the earth at sub-sonic speeds.

Even an object the size of an interplanetary probe hit the earth at sub-sonic speeds. Take for example the Genesis probe, it was travelling at 24,706 mph when it first encountered the earth's atmosphere, but when it hit the ground it was only travelling 193 mph.

It is quite plausible that microbes or some other form of life BURIED in a meteorite could survive the plunge down an exo-planets gravity well and atmosphere.

You are also assuming that the exo-planets atmosphere is the same density as Earth's. Again it is very possible that the exo-planets atmosphere is very thin compared with Earth's meaning small objects have an even better chance to survive the plunge.

Re:Sub 1cm Ejecta

[geekoid]

depends on the atmosphere and speed, but probably. Of course, 'burning up' doesn't mean the mass goes away, just changes.

Re:Sub 1cm Ejecta

[ceoyoyo]

Some of them are big enough, others hitch a ride on comets or asteroids.

There are pieces of Mars littering Earth. It happens.

Re:Sub 1cm Ejecta

[RivenAleem]

Burning up usually turns 'live' mass into 'dead' mass though.

Re:Sub 1cm Ejecta

[bdabautcb]

I do not know enough physics to get this right, but oxygen is required for combustion. The early earth didn't have much oxygen in it's atmosphere. Do things traveling through a non-oxygenated atmosphere combust, or get superheated, or what?

Re:Sub 1cm Ejecta

[Anonymous Coward]

One or two objects in this size range hit earth almost every day. They are called 'Meteorites' and can be purchased in any well stocked Rock Shop. They turn up thousands every time they do a search for them in Antarctica. but many are found in all countries of the world.

Rocks from the Moon or Mars are quite rare, but are found. How would we be able to tell if a rock was from another planet? we probably wouldn't until after we were able to visit that planet. Then we would be able to identify the tektites from the rest by isotope analysis.

Oh, and since you seem unaware of it, meteorites don't melt then vaporize on the way down. They ablate. Only a small surface melts and then boils at any time. There just isn't enough time for the entire body to come up to temperature before it hits.

Bacteria can take really extreme accelerations, with their small sizes. that's what makes them the most likely survivors. There are some species that also have thousands or even millions of times the radiation tollerance that we humans have. Plus, they freeze well.

Re:Sub 1cm Ejecta

[Anonymous Coward]

All it takes is one piece of gravel to hit. Yes, it's a trillion to one against for any single rock to hit, but, in a large impact, there are many trillions of such pieces sent out. That means that the odds are still greater than one to one over a several Million Year time frame, out to about 20 Light Years. Then, the newly 'infected' planet will, upon it's next massive impact (In our solar system, that is once every 50 million years on average) that system will in turn begin seeding the Galaxy itself. A chain reaction insues.

Oh, and such large impacts happen much more often in a younger solar system. Ours is Middle aged. Most are younger than we are.

Really, the math for all this was worked out by Fred Hoyle and Wickramasinge.in the 1950's. The math holds up, and the biology seems to bear it out.

The more we look the more surprises we find.

Galactica

[SJHillman]

There are those who believe that life out there began here
Flung far across the universe, before there were tribes of humans...

is this how life started here too?

[Anonymous Coward]

The next question has to be, was the Earth injected with life too? Is this how life started on our planet?

Re:is this how life started here too?

[Anonymous Coward]

This is not the "next" question, you're just repeating the last point made in the summary.

Worth a read, but ...

[Trapezium Artist]

I've made a quick scan of the underlying academic article by Hara et al., along with one of my colleagues in a meeting here, who is closely involved in the issue of planetary protection (i.e. making sure that our spacecraft don't "pollute" the solar system bodies they fly to and land on).

Of course, this is a known issue in general: after all, there are meteorites on Earth which we know came from Mars, so the converse is obviously possible. But extending this to moons of Jupiter, Kuiper Belt objects, and even exoplanetary systems, and finding that a significant number of Earth rocks may have been dumped there is interesting. So, the article is worth a more careful read.

However, my antennae were sent into a state of high agitation when I saw that the article has been posted on the arXiV following its having been accepted to the infamous Journal of Cosmology. We've discussed that here before: I invite you to view the journal website (easily found by googling) and decide for yourselves how reputable it is.

Which raises the question of why Hara et al. chose to publish there. That I can't answer, obviously, but will keep it firmly in mind as I read the paper in more detail.

Re:Worth a read, but ...

[CrimsonAvenger]

Which raises the question of why Hara et al. chose to publish there. That I can't answer, obviously, but will keep it firmly in mind as I read the paper in more detail.

Because it's rather long on speculation and short on facts?

And because there's no way to test any of this for a very long time to come?

Re:Worth a read, but ...

[Confusedent]

Oh seriously, those people? They're always pushing panspermia stuff. Like that whole "discovery of microscopic alien life" thing last March. From what I remember of that whole thing, the journal itself isn't to be taken seriously. Their research on the meteorites might be good, but the fact it appeared in JoC doesn't make me hopeful.

Re:Worth a read, but ...

[Trapezium Artist]

Well, in principle the paper is a fairly simple series of mathematical equations which you could actually work out on the back of an envelope. The devil though is in the details, namely the numerical parameters input to those equations. While many of those are straightforward and well-known, some may enter that category of WAGs (wild-assed guesses), and it's quite possible that the equations are particularly sensitive to (some of) those. That's why it's worth reading, to try and figure out where the issues may be.

As for the testability side, you're right, of course: very hard. But again, since we know of Martian rocks having made it to Earth via this mechanism, we can at least start to use some hard numbers based on that to try and constrain the likelihood of the Earth rocks having made it to other planets / moons.

Re:Worth a read, but ...

[garyoa1]

"there are meteorites on Earth which we know came from Mars"

This always annoyed me. While we can assume they did... why do we assume this? We were never there. Just because some tests show it's features are the same doesn't mean it "absolutely, positively" came from there. Claiming we "know" they came from Mars is a pretty big stretch IMHO.

Re:Worth a read, but ...

[Anonymous Coward]

Well, the poster claiming we "KNOW" they came from MArs is a bit strong. Some smart folks really really THINK they came from Mars, and they have some really strong arguments (and data) to support that claim.

But there is always the possibility that they are wrong.

In that vein they are looking for rocks from Earth on Mars, also they are looking for regular ol' meteorites (which I think have been found by the rovers).

Re:Worth a read, but ...

[Trapezium Artist]

Sorry, you're both correct: to say that we "know" was perhaps too strong a statement on my part. It was just meant as a scientific shorthand for "some smart folks really really think they came from Mars and they have some really strong arguments (and data) to support that claim", as you wrote.

It might have been better to say something like it is strongly believed that, or it is very likely that, or the most likely interpretation is that, or there is a very strong case for, and so on. But it's a pretty common shorthand in science to say "we know", and everybody understanding what is meant by such a statement without delving into the deeper recesses of epistemology.

In answer to the point made that "we were never there", err, where? Mars? No, we, as people, were not; but we, via some pretty capable robots, were. One of the fundamental pieces of evidence that scientists use to justify the claim that we have Mars rocks on Earth is that trapped gases in them have an isotopic ratio that matches that of the Martian atmosphere as measured by Viking, not that of Earth.

Absolutely, positively? No, science doesn't deal in those statements. Based on all available evidence, so likely that it's perfectly reasonable to effectively rule out nuttier alternatives? Yes.

the dark side of the moon IS A TRAP!

[Anonymous Coward]

"I mean the people when you look at them or talk to them it's like there clueless and their mind is off in outer space.And even a simple conversation seems like something their not capable of,whats up with them."

I swear there is another, even larger thread about this same issue. Maybe more people are just waking up to this. When you're in a place where people are waiting or in transit in large groups, a Subway, a Bus station, etc. in checkout lines in stores, at amusement parks in long lines, etc.

(I am not promoting or suggesting you or anyone watch one or any of the following films. I haven't since I've awoken and I intend to avoid them from now on):

Films that have always bothered me when considering what you've said, in the real world:

* They Live: but what if he was going *too* far and these *aliens* were just possessing the people and he saw the evil which was front and center while the human was "asleep" (Matrix possible connection) in the background of the mind?

* Truman Show: if not "one" individual, what of "millions" all duped by another race?

* Dark City: what if not only the "dead" were/are being used as vessels, but living ones
as well? (remember "Dax" from ST:DS9? and her "parasite" like being inside her?)
Something interesting if you should ever watch Dark City, potential spoiler,
one guy who "woke up" was concerned about "them" getting to him, so he found
a way out, and he jumped in front of a train to his death..
if you go frame by frame around the time or after he jumps in front of the train,
or press pause exactly at the right moment (it's difficult to spot if you use
pause) there is a poster on the wall, where one normally wouldn't be in real
life, and it mentions HELL, I forget what it says exactly, but HELL is mentioned
on the poster. It's been a long time since I've sat down with Dark City, and
honestly I won't again, it's too jarring to the mind once you've explored all of
this Illuminati crap.

* Matrix: In my opinion the movie is a lie, IMOthe red pill symbolises the opposite, being
pushed into a frame of mind or (sub)reality in which you are a puppet and controlled.
vs. "awakening" to truth, instead you are "deceived" through lies. Symbolism of
the creature taken from Neo could be related to a soul or more likely a protective
(holy) spirit, extracted by Satanists. The whole "Matrix" world, when viewed in
reverse (no, I don't mean watching it from ending to beginning) and perverted *for*
Satanist world-view/goals is eye opening, the same with Dark City. This movie only
bothers me, not for the fake/real awakening/reality concepts but in that I feel
the whole movie, IMO is a lie and the real meaning is perverted, kind of like..

* Fight Club: On many levels this movie bothers me, but I see the dark female character in the
movie as an evil angel which is involved in the split of the two identities of
the one leading role. In the same way I perceive her role in the film I see the
same, or feel the same vibe for the role of the female evil creature in the movie..

* The Ninth Gate: both the "odd" female role in this and in Fight Club shout out to me in
that they are both playing a similar or the same role. Please don't watch
this movie, I'm sorry I ever did.

#
This one, not so much as the method of alien attack as for how it sometimes "feels" for the person played by NK, in public once they've awoken to the aliens around them and how they act, or rather what actions the aliens DON'T display:

* The Invasion (I) (2007) | Nicole Kidman in lead role
http://www.imdb.com/title/tt0427392/

Tucker: When you wake up, you'll feel exactly the same. (possible tie-in to the movie, "Dark City")

"As a Washington psychiatrist unearths the origin of an alien epidemic, she also discovers her son might be the only way it can be stopped."

Yorish: I say that civilization is an illusion, a game of pretend. What

Re:the dark side of the moon IS A TRAP!

[rossdee]

Really? Is that like if you play it backwards you hear the voice of the devil or something
Noom eht yb despilce si nus eht tub enut si nus eht rednu gnihtyreve

The GRAND Delusion - how to beat it!

[Anonymous Coward]

The Final Battle Is For Your Mind And Soul!

Google: The Mind Has No Firewall, it's written by the military and is a must read!
:
Until they have plugged us all into the internet with our minds and keyboards/mice are tossed behind us, ways to ID us in every aspect of our lives will continue, because the machine of blackops is never satisfied, never full. It won't be until we're all hardwired into the global manufactured, false reality, second life like abomination of Internet 6.0!

Smartphones = lie with a sweet name
patriot act = lies with a sweet name

Just as I'd imagine they'd call some type of legislation against Christianity, the "True Cross act of 2029!" it's all a big game of lies, folks! Lies!

Your soul is what they're after! Rebuke all entities trying to communicate with you in the name of Christ Jesus, Yahweh, Holy Spirit, watch them run, watch them flee! They are scared of the mighty One True God. Do not be fooled by darkness, it has no real power.

But there are those who will accept what these evil entities have to offer, delusion and a false belief they've gained hidden knowledge. Remember, "nothing is new under the sun".

Everything hidden will be exposed when God returns, and the evil creatures fear Him, and rightly so! The humans who have been lulled by these evil entities are afraid, too, they do their best to bash precious Christ, but they will be defeated in the end, unless they choose God. They will be thrown in the same lake the invisible serpents and scorpions will be thrown into.

The "don't tread on me" flag is illuminati garbage, the same snake image is on Metallica's black album cover. The Bible gives Christians the power to TREAD ON SERPENTS AND SCORPIONS and OVER ALL POWER OF THE ENEMY. These are mentions of real, spiritual enemies! They should be tread upon at all times! They are weak but God is strong!

They're running ANCIENT ALIENS on THC and aliens everywhere, occult symbolism in everything you could imagine, popular music, movies, television shows, comics, entertainment magazines, you only need to know what to look for, this whole world is polluted by the occult, they want you to kneel on the commands of evil, do not fall for the trick, do not fall for the false illumination, come to Christ and CLAIM the power over ALL EVIL!

Never forget: The beast system longs to trick and absorb us all, for any true Christian is a threat to the beast system and its lies.

When you gain confidence in your faith, they will send messengers in human likeness or humans taken over to try and pollute your belief, to try and sway you from your faith. If you follow a paganized form of Christianity or give up your belief, the attacks will not be as pronounced, or they may stop altogether, for you will have "fallen away" and aren't a spiritual threat.

WE are ETERNAL beings, the powers of darkness despise this and want to rob us of our heavenly place in our heavenly home.

Avoid ghost-hunter shows, anyone searching for ET or other such garbage, they are all manifestations of the same evil. Trust God and His Word. People posting against this truth are likely a part of the delusion.

The cover of The Dark Side of The Moon album is illuminati proof, summed up in one photo, of a (spiritual) transformation which is a lie. Don't be fooled by creatures appearing as light or bathed in light or blinding you in light. Reject them all through Christ and they will flee like the cowardly vermin they are.

Re:The GRAND Delusion - how to beat it!

[Confusedent]

It's all so obvious now.

Re:The GRAND Delusion - how to beat it!

[doston]

You should teach this in Tennessee!!

Truecrypt Tor RAM and TALK 2 THE HAND!

[Anonymous Coward]

Theres a lot to be said about running The Tor Browser Bundle in an encrypted container (TrueCrypt) on a LiveCD, with the hard drive UNPLUGGED and UNUSED!

(just take the hard drives out and never use them again, USB thumb drives are cheap and can be encrypted with TrueCrypt, too, as an encrypted containter, partition, or the whole drive itself, just never use a proprietary OS like Windows or Mac OS X)

As a primer, read:

#Tor OPSEC Operational Security
Great Resource of Information!

cryptome.org/0005/tor-opsec.htm

And:

#Lest We Remember: Cold Boot Attacks on Encryption Keys

citp.princeton.edu/research/memory

If the keys (TC passwords) are in my head, complex enough, and never written down.

With the amount of RAM present in new computers, I see no logical reason to use a hard drive again when Linux LiveCDs, encryption, and thumb drives are on the cheap or free.

No unsafe hardware sex, either, this means no plugging your Tor/Truecrypt thumb drive into another system, any system, except for your Tor/Truecrypt system.

Run audits on your system, verify LiveCDs, make sure your router isnt backdoored like many or maybe all of the Cisco routers. Keep up to date if you use open source firmware for your routers. Consider replacing proprietary routers with an older PC as a router with an open source OS like OpenBSD or a prerolled firewall distro.

Test your connection with remote nmap, dabble with Snort, Tripwire and other monitoring tools.

Dont use external hard drives.

RAM is your friend, always.

Re:Truecrypt Tor RAM and TALK 2 THE HAND!

[JustOK]

ur never safe until you start making your own processors.

Tasty aliens...

[mevets]

If we share common ancestry, that means we might find alien life tasty and nutritious. ... to seek out new life and new civilizations, to eat.

Re:Tasty aliens...

[ZeroSumHappiness]

To Serve Man, anyone?

Re:Tasty aliens...

[FoolishOwl]

Panspermia seems like it would make for a good handwave in science fiction why humans could find edible food on an alien planet, or have to worry about alien diseases. I have a hard time believing life could actually spread from planet to planet this way. But I'm not a physicist or biologist.

Re:Tasty aliens...

[GodfatherofSoul]

But, whoever develops interstellar travel first will no doubt have the technological edge to be the taster and not the tastee. Why was E.T.'s belly so big and were Reese's Pieces a favorite garnish?

Re:Tasty aliens...

[Anonymous Coward]

You know, we share common ancestry with cockroaches and slime mold...

Really?

[srees]

I had no idea the theory of an asteroid impact had been proven as fact. Glad I read slashdot so I can stay educated.

Re:Really?

[geekoid]

yeah, it's a fact. Giant craters, layer of material around the globe. etc...

Fermi's Paradox solved.

[tekrat]

So, without realizing it, we're ALREADY colonizing our galaxy. Life bearing rocks from earth hit other planets, those planets also experience trauma sooner or later, ejecting their rocks into space millions of years later, after life had caught on, and so on and so on.

Therefore, Earth may be a colony of some other civilization from billions of years ago, or, we're creating colonies as we speak.

You are exceptional

[exploder]

Astounding! With just a few minutes of thought and your superior intuition, you've dismissed the result of careful calculation and decades of training on the part of this group of scientists. Imagine what a genius of your magnitude could accomplish from within the scientific system...it truly staggers my humble intellect! But I'm sure you're working on much more important things.

Re:You are exceptional

[flyneye]

Noticing that the king wears no clothes is one thing, and not appropriate, but yes, I question the absence of his codpiece.
Now if you have any information about the physical absence of his genetalic cover, I would appreciate some of this insight your fanboys have endowed you with.

Re:You are exceptional

[ceoyoyo]

You're just a trash tabloid staff editorialist unless you actually read the paper and comment intelligently on their methods. I suppose you might get some play on the National Enquirer... I mean Slashdot, but that doesn't make you clever or insightful.

Re:You are exceptional

[flyneye]

I really wish I could get all you guys to see all the posts, this has potential for a fun conversation if you increase your perspective.
Relax, grab a beer( unless it's too early there) and let's think about this.
I'd say it would even be a treat if we all skimmed some of it, had our little thread thingy, made our "BETS" as implied originally, then go back for some research from our perspective.
  I bet you give gifts unwrapped, don't you?

Re:You are exceptional

[ceoyoyo]

Sorry, you've lost me. I read the whole thread. I was following your "emperor has no clothes" metaphor. What is it we're thinking about? Your vague assertion that "even making Europa would be kind of like hitting a cockroach with a needle from across a football stadium" followed by some silliness about Vegas and grants?

Re:You are exceptional

[flyneye]

It actually started with Vegas,grants and cockroaches in the stadium.
Odds, think odds and the criteria it takes to get it there.

Re:You are exceptional

[ceoyoyo]

Yes, your made up example of hitting a cockroach with a needle, that has nothing to do with what we're discussing. I realize your silliness, started there, with something you made up without actually reading the paper we're talking about.

Re:You are exceptional

[flyneye]

Well, WE talked about IT anyway. You just kinda sat here whining and still seem to be.
That was so six hours ago.No soup for you.

How did life survive the heat of the impact

[rossdee]

I could believe that some simple life form could suvive on a rock travelling through space for millions of years, but I don't see how it would have survived the heat of the impact event that blasted it beyond escape velocity in the first place

(at least life as we know it, Jim)

Re:How did life survive the heat of the impact

[Anonymous Coward]

What if it's in the rock?

Re:How did life survive the heat of the impact

[ceoyoyo]

Most non-dinosaur killing meteorites land cold.

Re:How did life survive the heat of the impact

[symbolset]

Myriad wonders the universe has. Bacteria that live two miles beneath the surface of the Earth. Bacteria that subsist on an energy cycle of direct heat conversion. Natural Fission Reactors that can provide energy for such bacteria for billions of years. Frost in interstellar space that condenses on the outside of anything passing through to impossible thickness. Supernovae that blast their planets to smithereens, spreading them across the galaxy.

Re:How did life survive the heat of the impact

[sackbut]

With large enough bits of rock - on the inside. There are bacteria that live within the rock up to 2-3 kilometers under the surface. I can see popping rock into the air/orbit further away from the impact site so they are not melted completely. Like snapping a towel. They would still be sunject to

I have difficulty with the millions of years in the vacuum of space being irradiated by gamma rays (that we use to sterilize things now). Bacteria will not survive hundreds to thousands, much less millions of years on Earth! How long does it take bacteria to die on your kitchen counter/door knob, etc? Usually minutes to hours. Only certain kinds of spore forming bacteria can survive dessication (drying out) even.

May I suggest: http://www.ncbi.nlm.nih.gov/pubmed/18225667 "One of the most important aspects of the problem of life transfer in the cosmic space is the resistance of microorganisms to high-temperature heating during the launch and entry into the atmosphere. The high-temperature limits of the survival of microorganisms were studied under conditions modeling the laungh from the Mars and the landing on the Earth. Two strain of E. coli K12 exposed to short heating pulse were studied in order to tind out if they could resist high temperature while being in the desiccated state. The procedure was performed in vacuum. It was found that a fraction of bacteria survive heating pulses up to 250 degrees C in vacuum, while similar heating at normal atmospheric pressure leads to the total sterilization of samples."

Aliens not so alien?

[Anonymous Coward]

So the implication is that if this is true then if life is one day to be discovered within the subsurface oceans of either Europa or Enceladus then it's possible that such life originated from Earth, and therefore from the same root single celled organism (the Eve cell) from which all terrestrial life came from. If so a mitochondrial DNA check would verify this.

Re:Aliens not so alien?

[Anonymous Coward]

Confirmation of why all the aliens on network sci-fi were humanoid! And why the aliens on Aliens found us so tasty!

ummm...?

[um... Lucas]

How can we study the trajectory when we don't know:

When the asteroid hit?

The earth's position relative to the sun, the other planet, and the rest of the stars in the galaxy at the time of impact.

The direction from which the asteroid hit us.

The size of the asteroid.

For starters....

Re:ummm...?

[Anonymous Coward]

Came here to find the answer to this very question. I'm surprised no one else is asking it.

An OK theory for other planets, but not ours?

[jmulvey]

Panspermia is a very interesting/compelling theory. But I'd avoid telling anyone in academia that you're interested in an Earth genesis hypothesis other than evolution.
You may just as well have told them that you're a pro-lifer, who voted for Bush, are home schooling your kids, believe in a balanced budget, and are a racist all in one sentence.

Re:An OK theory for other planets, but not ours?

[blueg3]

Evolution isn't an origin-of-life theory. You're thinking of abiogenesis.

Re:An OK theory for other planets, but not ours?

[Hatta]

I'd avoid telling anyone in academia that you think evolution is an "Earth genesis hypothesis".

Re:An OK theory for other planets, but not ours?

[ColdWetDog]

Oh bullshit. Panspermia has been around for decades and lots of mainline scientists (including Francis Crick, one it's earliest proponents) have thought it interesting.

But it is more entertainment than anything else - until we get off planet enough to test it. A dozen probes to Mars and a Europa would be good start, but as always - if you've got the money, I've got the time....

Re:An OK theory for other planets, but not ours?

[Froeschle]

But it is more entertainment than anything else - until we get off planet enough to test it

If something cannot be tested then it's not true even if it appears highly plausible. The existence of exoplanets was also hotly debated in the same manner right up until the first one was found. What is so far fetched about the idea behind panspermia? All of the material we see around us here on Earth originally formed inside previous generations of stars and much of it may have been incorporated into previous generations of planets. Bacteria can be found inside rocks here on Earth so why can't some very big very old rocks containing bacterial "spores" from long since vanished planets not have ended up on Earth or anywhere else within or outside of our galaxy? The universe is very very very old so life surely has had more than enough time to flourish die and spread inside rocks of any size.

Wait

[Anonymous Coward]

All this talk about ejaculates and sperm theory, and NOBODY's made a joke about it yet?

Martin Lo's low energy trajectories

[mattr]

Actually Martin Lo discovered low energy gravitational paths or "superhighways" that would allow objects like space probes and maybe rocks to travel all around the solar system without power. These calculations were used in the Genesis probe NASA project IIRC.
http://en.wikipedia.org/wiki/Interplanetary_Transport_Network
http://genesismission.jpl.nasa.gov/gm2/team/people/lo/interview1.htm

Re:Martin Lo's low energy trajectories

[flyneye]

Now that's a consideration too, another spin of the wheel in space-Vegas.
Might an x % or even all of this be stuck on some pan-galactic Nascar track to nowhere?
I wish I could get all you guys to see each others posts and ideas to add to the odds, it would make this thread a blast!

Re:Martin Lo's low energy trajectories

[flyneye]

And yes that increases the odds of it hitting something in our system, acknowledged. But the value of icy chunks landing on an icy surface with our homegrown life starts then being able to evolve usefully in this amount of time is in question. The Mars thing would be cool and it would give some "Enquirer prestige " to some Russian Scientist rumoured to have seen a "scorpion" like thingamadoo on a Venus pic. (lol, maybe that was the Enquirer someone told me about)

simple math, brought to you by Google Calculator

[Lluc]

Assume we're just dealing with Carbon (molecular weight 12) here, and "well over 1 trillion tonnes" is actually 2 trillion tonnes:

number of molecules per gram = (Avogadro's Number) / 12 grams = 5.02E25 molecules/kg
2 trillion tonnes = 2E15 kg
(5.02E25 molecules / kg * 2E15 kg) = 1.004E41 molecules

Surface area of sphere with radius of 20 light years = 4.499E35 meters^2

1.004E41 molecules / 4.499 meters^2 = 223,091 molecules / meter^2 == 4.44 attograms of carbon per square meter.
This is a pretty thin layer of material to survive reentry on some 20 light year distant planet.

--------
Alternatively, from google: ((Avogadro's number / (12 grams)) * (2 trillion tonnes)) / (4 * pi * ((20 lightyears)^2)) = 0.223099739 kilometers per liter = 0.5 miles/US gallon, which means we totally need to collect some gas guzzler tax on this material

it's a FACT. it's on WIKIPEDIA.

[Thud457]

Don't forget that the movie WALL-E syncs up perfectly with Pink Floyd's "The Wall". A bloody obvious giveaway that you're trapped in The Matrix.

Krrryptonite!

[Anonymous Coward]

Somewhere on Gliese 581's "Earth" is a Lex Luthor dinosauroid plotting the demise of Supersaur using radioactive fragments from his home world.

Re:simple math, brought to you by Google Calculato

[ceoyoyo]

Fortunately rocks aren't light. Their atoms tend to stay clumped together instead of spreading out uniformly like photons.

tired...

[Thud457]

To Serve Man

From my limited experience with mankind, more like " Silence of the Popplers ".

Panspermia?

[Anonymous Coward]

That's what she said.

the hard six

[Eponymous Hero]

that's how i roll

Re-entry may not be that challenging

[onyxruby]

Just a thought here, but I don't think re-entry would be that challenging for bacteria based life to survive. Most people think that what left of an asteroid is really hot when they land, but that just isn't the case. In fact asteroids have been touched right after landing and described as 'cool' in temperature.

http://impact.arc.nasa.gov/news_detail.cfm?ID=1

If bacteria were in the core part of the asteroid that survived impact it should be reasonable to assume that the part that is cool to the touch never got hot enough to kill any bacteria that were inside it. The other two questions than become what kind of shock (g-forces) can bacteria survive? We know they can survive the shock of being launched into space, and without the squishy bodies that we have they may well survive the shock of re-entry.

If we could determine the answers to those questions than really the only questions remaining are can bacteria adapt to their new home? We already know they live in places on earth that are very inhospitable by our standards. The only other real question is how long can they survive in space? We have documented cases of bacteria surviving in space for years at a time. If there is no real limit to how long they can survive in space than cross solar system colonization is all but inevitable.

Re:Re-entry may not be that challenging

[kermidge]

Tardigrades (water bears) might have a chance. http://www.wired.com/wiredscience/2012/04/tardigrade-eggs-space/

IIRC, some spores might also do so.

Decelerate fast and drift down?

[Anonymous Coward]

I would expect they would decelerate pretty quickly, the mass / cross sectional area decreases as the 1/3 power of mass. Then they would fall at terminal velocity, which will be quite low for any reasonable atmospheric density, and wouldn't bother bacteria at all when they hit the ground.

Particularly if the ejecta are e.g frozen droplets of seawater, life could be distributed throughout, and you'd only need a tiny fraction of the ice to survive the decelration event.

I am amazed at the lack of understanding here

[Anonymous Coward]

I am amazed at comments by otherwise likely intelligent people here on Slashdot who still have absolutely no concept of just how complex even the simplest replicating organism is. Are the majority of people still so ignorant as to believe if you put a bunch of amino acids in a box and shake it long enough a simple replicating cell will emerge in time?

I am not a creationist, but I am also not purposefully ignorant about the issues surrounding life's origins. Perhaps someday by applying sciences like complexity theory we'll discover a way in which life an originate naturally and easily, but based on the extent of our knowledge right now life is far too complex to have arisen by chance in 500 million years on Earth.

To confidently say life arose naturally on Earth is a RELIGIOUS VIEW, an ARTICLE OF FAITH, akin to the creatioist view that God created life.

So what am I saying? That we need to be honest about the mystery of life's origin and not dogmatic that it somehow sprung magically from unliving matter on a young Earth just because we believe the only alternative is God and we don't want to believe in a God.

Personally, because I know how incredibly improbable it is that life could arise naturally in such a short time on a young Earth I feel the theory of panspermia (life everywhere) is the only current probable explanation. We used to think the Earth was the center of the Universe and people still haven't gotten over the prejudice that life must have arose on Earth because Earth must be the center of life. Stretch your knowledge people and don't be such dogmatic evolutionary fundamentalists.

Proposal

[Roachie]

We are alone in the universe, the only life is what we know here on the Earth.

Survivable ejection?

[Anonymous Coward]

How could organic matter survive ejection?
In order to reach such orbits these fragments have to be traveling at more than 10Km/s. In fact, considering the decceleration the atmosphere would cause they would have had to start at way more than that. Such speeds across the atmosphere would disintegrate any particle smaller than a few decimeters in size. I don't see how life could survive anything like that on a rock smaller than a few meters in diameter.

"65 million years ago"?

[Friendly_Zergling]

I tried to purchase a radioactive Carbon dating machine so I could age some rocks and bones, but unfortunately I could not find any such machines for sale. I have no way of aging rocks, bones, or fossils. Do you? So what scientific method, if any, was used to back up the claim that this event occurred "65 million years ago"?