Chicxulub Impact Might Have Spread Life-Bearing Rocks Through the Solar System

KentuckyFC writes "Some 65 million years ago, an asteroid the size of a small city hit the Yucatan Peninsula in what is now Mexico, devastating Earth and triggering the sequence of events that wiped out the dinosaurs. This impact ejected 70 billion kg of Earth rock into space. To carry life around the Solar System, astrobiologists say these rocks must have stayed cool, less than 100 degrees C, and must also be big, more than 3 metres in diameter to protect organisms from radiation in space. Now they have calculated that 20,000 kilograms of this Earth ejecta must have reached Europa, including at least one or two potentially life-bearing rocks. And they say similar amounts must have reached other water-rich moons such as Callisto and Titan. Their conclusion is that if we find life on the moons around Saturn and Jupiter, it could well date from the time of the dinosaurs (or indeed from other similar impacts)."

Comments

And Vise-Versa

[Press2ToContinue]

A nice example of panspermia.

Re:And Vise-Versa

[MightyMartian]

A nice example of how panspermia might happen. It's a helluva leap between having life-bearing rocks blasted off of earth by a massive meteor collision, and quite another to suggest that the rest of the solar system could have been seeded.

Re:And Vise-Versa

[Zantac69]

Exactly - as life on earth may have been seeded from Mars, Venus, or....somewhere out there.

Re:And Vise-Versa

[SJHillman]

There are those who believe...that life out there began here, far across the Solar System...with tribes of dinosaurs...who may have been the forefathers of the Europans...or the Callistians...or the Titans...

Some believe that there may yet be descendants of microbes...who even now fight to survive—somewhere beyond the heavens!

Re:And Vise-Versa

[Anonymous Coward]

A nice example of tacking a huge list of assumptions and estimates together. I would like to see that list...

Re:And Vise-Versa

[bob_super]

Seconded.
That's a really long trip to be taking in the life-unfriendly vacuum.
And at the end you land pretty hard on something no quite like where you grew up.
Liquid water? Check!
Photosynthesis? Hope you brought it with you!
Other food? Not Mexican!
Gases? See above.

Re:And Vise-Versa

[ShanghaiBill]

A nice example of how panspermia might happen. It's a helluva leap between having life-bearing rocks blasted off of earth by a massive meteor collision, and quite another to suggest that the rest of the solar system could have been seeded.

It is a much, much, much, bigger leap to suggest that such impacts could lead to the transfer of life between star systems. Panspermia usually refers to the hypothesis that life spread throughout the universe, not just between planets surrounding one sun.

Re:And Vise-Versa

[ShanghaiBill]

Liquid water? Check!

Maybe not. Europa is believed to have an ice layer between 10 and 30 km thick. It is unlikely that an impact by a 3m rock would penetrate more than 100m or so. The impact would melt some water, but it would quickly refreeze. Europa's surface is pocked with craters millions of years old, so there does not appear to be a regular turnover of the ice that would carry any surviving life to the ocean below.

Re:And Vise-Versa

[SJHillman]

Baby steps. Let's give it a few million miles before we start looking at light years and surviving interstellar space.

Re:And Vise-Versa

[Anonymous Coward]

No no no! All lies! We all know Jesus had a pet dinosaur!

Re:And Vise-Versa

[Runaway1956]

I believe that article has things upside down. My introduction to the concept of panspermia suggested that life originated in space, then was slowly introduced to planetary surfaces. The idea that life is spread by catastrophic impacts on planetary surfaces seems far less likely than simple space critters evolving after landing on a planet.

Re:And Vise-Versa

[TWiTfan]

The Battlestar Galactica fleet?

Re:And Vise-Versa

[hubie]

From the first paragraph in their paper:

Panspermia is the hypothesis that life can be spread between planets and planetary systems. One class of panspermia is lithopanspermia, in which pieces of rock are the mechanism for dispersal (Tobias & Todd, 1974; Melosh, 1988). Rock fragments can be ejected from an inhabited planet's surface via large meteor impact. This ejected material can then travel through space and may land on another planet or moon, as we have seen in identified meteorites from Mars found on Earth (Bogard & Johnson, 1983; Carr et al., 1985). If an ejected rock encases sufficiently resilient organisms, life could be seeded on its destination planet or moon.

Re:And Vise-Versa

[Charliemopps]

Europa has liquid water geysers, and fissures that routinely open up and then re-freeze. Think of the top layer of ice as our earths crust and the (possible) liquid ocean beneath like our liquid rock core. The surface ice shifts constantly and allows briney water to escape to the surface before it re-freezes.

Now, what are the chances that a microbe laden rock would land in one of these crevasses? Pretty low, but keep in mind it's frozen, and could remain frozen on the surface for a very long time waiting for a crack to open beneath it. The odds are still pretty low I admit, but then keep in mind that these large collisions, microbe laden asteroids and Europa's ice flows have been going on for billions of years. Even if the odds per event are almost nil, the cumulative effect is staggering.

When I think of space, I find it hard to believe anything is "impossible" given the vastness and near timelessness of it all. Granted there are some universal physical laws (speed of light) that make some things impossible. But anything that is simply "very very unlikely" has probably already happened.

Re:And Vise-Versa

[Anonymous Coward]

Tribes of dinosaurs? That would be the Voth for you.

Re:And Vise-Versa

[Anonymous Coward]

why is that? What is there in the void of space that makes you think life will just "happen" ? At least on planets there is a veritable soup of energy and compounds to eventually hit the right combination to form life; life at least as we know it.

Re:And Vise-Versa

[Livius]

True.

But leaps happen.

Re:And Vise-Versa

[hubie]

This is addressed in the paper. The paper abstract:

Material from the surface of a planet can be ejected into space by a large impact, and could carry primitive life forms with it. We performed n-body simulations of such ejecta to determine where in the Solar System rock from Earth and Mars may end up. We find that, in addition to frequent transfer of material among the terrestrial planets, transfer of material from Earth and Mars to the moons of Jupiter and Saturn is also possible, but rare. We expect that such transfer is most likely during the Late Heavy Bombardment or during the next one or two billion years. At this time, the icy moons were warmer and likely had little or no icy shell to prevent meteorites from reaching their liquid interiors. We also note significant rates of re-impact in the first million years after ejection. This could re-seed life on a planet after partial or complete sterilization by a large impact, which would aid the survival of early life during the Late Heavy Bombardment.

Re:And Vise-Versa

[MightyMartian]

Most panspermia proponents I've seen (of the Hoyle variety) seem to be a little shy on any specific details other than a sort of a Battlestar Galacta-esque "life here began out there" kind of line. There's no real substance to their "theory" beyond a "golly, it sure seems unlikely abiogenesis happened here, but somehow, someway, it's more likely somewhere else in the Local Group."

Most of the what I woudl consider legitimate "xenobiologists" don't really look beyond the solar system. There are some that think Mars might have been more hospitable early on, so maybe life began there and then caught a ride after some sort of a meteor impact with Mars that reached Earth. But really, as sparse as the evidence for abiogenesis on Earth is, thus far we have no evidence that in any way approaches conclusiveness that there was life on Mars. And even if we do find it, you still have to show some sort of a genetic relationship between life on both worlds (or indeed, on any other body in the solar system) and life on Earth.

In other words, yes, it's likely that the major meteor strikes on Earth over the last 3.5 billion years have shot life-bearing rocks out into space, but while it seems likely that some may have made it to other bodies in the solar system, it's a helluva a leap from that to "hey look, Earth life flourished on Mars or Europa."

Re:And Vise-Versa

[Derek Pomery]

Hm...

Well, from the actual research paper...
"They estimate that a rock of 3 m across shields D. radiodurans for 10 Myr, and 3.3 Myr for B. subtilis"

10 million years is a loooong time. The simulations were calculating in the mere kiloyears according to the paper.

Take oneof the higher ejection velocities... 12.41km/s - let's make it a nice round 10km/s.
Aaaaand, pick a solar system near-ish to us, that is known, like 10.5 light years away. Call it 10^14 km away...

That's a mere third of a million year transit time. So, like a mere 3% of the survival time for Radiodurans w/ a direct trajectory. And ofc, it doesn't necessarily have to survive fully capable to replicate. Even a bunch of starter DNA would be a big help to the new planet.

Re:And Vise-Versa

[Samantha Wright]

It's pretty problematic that the impact in question happened in Mexico. The Yucatan isn't exactly a haven of extremophiles—you wouldn't expect to find anything that can maintain a biosphere without a good light source, and they're definitely not well-adapted to the sulphur and magnesium contamination that Europa appears to have. Unfortunately the best places to find organisms with a chance of surviving in this kind of environment are at the bottom of the ocean, which is a particularly bad target for producing ejecta. Caves are also a possibility, and since Mexico has no shortage of them, they might be a potential avenue... but who knows if there were any decent ones in the Yucatan at the time.

Re:And Vise-Versa

[symbolset]

Not really. Somebody computed the likelihood of Chicxulub material making its way to the nearest stars and found it not only a certainty, but they were able to estimate the total mass per neighboring star, the time en-route, and so on. In the roughly 3.5 billion years since life arose on Earth the sun has made 17 laps around the Milky Way. The Oort cloud is fairly well polluted with life. Sometimes a star comes a little too close, and we do some border trade on the frontier. Interstellar comets pass through every year gathering up a little bit on their lonely journey. Sometimes they run into things, and leave a little litter from what they've picked up on their road trip. Consider that the Milky Way had an 8 billion year head start on us, and the conclusion is obvious.

Space is big. Really, really mind-bogglingly big. But time is also long.

Re:And Vise-Versa

[Anonymous Coward]

Copulating planets via ejecta.

Re:And Vise-Versa

[TapeCutter]

There are those who believe...

*The emperor rises to his full height slapping his testicles together in applause*

Bravo Court Jester, another wonderfully funny and politically astute show. Your best show yet - if I may be so bold as to critique your art.

*For the first time during the evening, the audience is silent, you can hear the tension in the air but nobody dares so much as a whisper*

Let it be known to my court, there are some in the empire who take their sci-fi too literally and talk of the solar system as a real place where Europeans - or whatever they're called - exist.
We must all take care not to confuse reality and fantasy in our daily conversations because such talk without the sharp comedic wit of a professional artist is a threat to our very survival. As we know it promotes the heinous crime of irrational thinking when it's is plain for all to see that there is nothing beyond the celestial ice dome but more celestial ice dome. What is it about "ice all the way up" that is so hard for some in my court to comprehend? Well I believe Octopus' razor tells the court that nobody is that reallystupid, the best mathematicians of the court are all convinced the stories are a sophisticated code for subversive activities of the court's enemies. They must be stopped or they will rip the court asunder!

*Set to sinister music* - The emperor slowly withdraws back into his emerald green exoskeleton until only his four eyestalks are visible to the audience, all the while taking mental notes on those who are not enthusiastically applauding his own politically pointed performance.

Re:And Vise-Versa

[ShanghaiBill]

The Yucatan isn't exactly a haven of extremophiles

There are extremophiles everywhere if you go deep enough. Endoliths (organisms that live inside rocks) have been found at depths of 3 km, and probably commonly live even deeper. Endoliths can endure temperatures of 120C (250F), and have also been found in the extreme cold and low humidity of the Dry Valleys of Antarctica. If anything can survive the journey to Europa, it is probably an Endolith.

Re:And Vise-Versa

[Anonymous Coward]

You forgot to mention that going zero-to-mach-30 in less than a millisecond is hostile to most forms of everything living or not living. I've yet to ready a paper by an theoretical paleo-astrophysicist that talks about hard-earth impacts yet shows any reverence for escape velocity of such mass and the ludicrous acceleration it would require/undergo, and what sort of energy conversion it would undergo. Anything that left Earth's atmosphere (that was once a 3-meter diameter rock) was lava by the time it was a foot off the ground.

Re:And Vise-Versa

[Samantha Wright]

I was thinking that might be the trick, although the region is still not very suitable for honing and maintaining cold-weather survival skills. Here's hoping the crater was pretty deep.

Re: And Vise-Versa

[Anonymous Coward]

I think you might be thinking of Enceladus, a moon of Saturn. Some have hypothesized that similar water jets might occur on Europa, but I don't think there is any evidence of that.

Re:And Vise-Versa

[philip.paradis]

Indeed.

Re:And Vise-Versa

[philip.paradis]

Oh my, that was supposed to be a link to a Philosoraptor pic, but it appears I had to wrong URL in my buffer. Sorry about that, folks!

Re:And Vise-Versa

[VortexCortex]

The Yucatan isn't exactly a haven of extremophiles

Whom were ancestors of the extremophiles? Only other extremophiles, or have they sprang forth from more nominal relatives? When I consider that getting trapped under a glacier has caused live to live with little or no oxygen (blood falls), I often wonder just how hard it is to become an extremeophile? Perhaps the extremophiles really aren't so extreme after all? Perhaps every environment can be seen as extreme depending on your point of view.

I mean, here on earth we have life using a sulfate catalyst to respirate via ferric ions -- A metabolism never before seen anywhere else. One season the ice forms above a pool of water, and just never recedes -- Surely, one would assume certain death of all life therein... and be very wrong, indeed. I can't bring myself to form strong opinions of the conditions under which life can not survive...

Unfortunately the best places to find organisms with a chance of surviving in this kind of environment are at the bottom of the ocean

Interestingly, we used to think that NOTHING could survive at those depths, yet they are teeming with life. This is a "problematic" situation, indeed. Forgive me, if I'm skeptical of pessimism: My arrogance and chauvinism has been worn down over the years by nature proving my brain not special, and its thinking wrong time and time again.

Re: And Vise-Versa

[Anonymous Coward]

Can we send the rest of Mexico to Europa? It would solve a lot of problems I'm sayin.

Re:And Vise-Versa

[FatLittleMonkey]

At least on planets there is a veritable soup of energy and compounds

Everything that exists in and on the planets of the solar system, baring that which chemically formed later, originated in the nebula from which the solar system formed. And studies of other nebula show the most complex organic molecules we can detect by spectrum. (Ie, each time we work out how to look for something more complex, we find it in nebula. Not very complex - we're only up to "Organic Chemistry 102": naphthalene, glycine, kerogens, multi-shell fullerenes, etc - but we haven't reached a limit yet.)

An entire solar system, not just the thin cruft on the surface of Earth but whole planets worth of dust and ice, mixing and colliding, sticking and breaking apart, in conditions ranging from in close to the forming sun to well beyond the ice-line. If life can form on very early Earth in just a couple of hundred million years amid the late-heavy bombardment, it can surely form in all that over the preceding billion or so years.

Okay, it might not, but it's an easy proposition to test, and if it did form there, it would mean life is everywhere. Which is what makes it so frustrating that no missions ever try to directly detect Earth-like extremophiles anywhere in the solar system. It's like watching someone trying to work out whether they are in the middle of a forest by taking temperature readings. "Just look for some freakin' trees!" "But it might not be that kind of forest." "And it takes one look to work out if it is!" "But that's only giving us one result and there's a lot of competition for funding..." "Argh! It's the result!"

Re:And Vise-Versa

[Anonymous Coward]

Actually it would be more like the impact returning life into space from which it originally came. I'm sure the same process happens throughout the universe and space is just full of rocks containing life that was blasted off billions of worlds. To think that any world is biologically isolated from the rest of the cosmos is foolish.

Re:And Vise-Versa

[Anonymous Coward]

Whom were ancestors of the extremophiles?

+5 funny. You misused "whom" trying to be so sophisticated and failed hysterically; who were anscestors. If you don't know when and when not to use whom, just don't. It just makes you look pathetically ignorant when you use "whom" incorrectly. Ever hear the phrase "faux intellectual"?

Wouud you say "he was ancestor" or "him was anscestor"? Saying "whom were ancestors" is akin to saying "him was ancestor".

My arrogance and chauvinism has been worn down over the years by nature proving my brain not special

Comedy gold!

Re:And Vise-Versa

[Samantha Wright]

Hold your horses: that shit takes significant amounts of time. Unless there were snow-topped mountains in the Yucatan, there was no ice to acclimatize to. It's easy to adapt to periodic ice—even if every single bacterium gets wiped out one year, new bacteria can still enter from the outside environment each year until an antifreeze protein is developed and a foothold established.

The more extreme the new conditions, the harder life has to work to adapt. As it is, there are only a handful of bacteria (examples) that can withstand the conditions typical of Mars, and they had a great deal of time to practice. And that's not counting the expected dose of DNA-shredding radiation, which is bearable by even fewer critters. (The tardigrade being one hilarious exception—but they go into hibernation mode when in space and would never wake up on Europa's surface.)

Interestingly, the Atacama Desert in Bolivia seems to have terrain high enough for bacteria to evolve considerable radioresistance, amongst other things. If the Yucatan had enough height at the time, there's a tiny chance it was a similar biome, but in general the Cretaceous period is known to have been very humid, so this seems unlikely.

Re:And Vise-Versa

[RockDoctor]

Maybe not. Europa is believed to have an ice layer between 10 and 30 km thick. It is unlikely that an impact by a 3m rock would penetrate more than 100m or so

The working rule of thumb for impacts at interplanetary speeds is that your impactor will dig an initial crater of about 10 times it's own diameter (and of surface diameter around 100 times it's own diameter), being vaporised in the process, and the large majority of the impactor then being ejected along with most of the impact site.

For your 3m meteorite, that's an initial crater of 30m deep, followed by flash sterilisation and ejection back into space as a silicate vapour with small amounts of water, carbon oxides and some ammonia. Touch of phosphoric acid. Snifter of sulphuric.

You need an impact cushioning system at the receiving end, i.e. an atmosphere. Which Europa (and all of the other Galilean satellites, doesn't have. (OK ; a weak pass for Io ; a few ten thousandths of a bar isn't enough though.)

To mis-quote Walter Matthau on the subject of killing your wife, "Splat!" (I think he used more exclamation marks.)

Re:And Vise-Versa

[RockDoctor]

There are extremophiles everywhere if you go deep enough.

Arguable (hint ; I'm a geologist, and I do follow this work) but I'll grant you the supposition. The problem is to get this stuff to an upwards escape velocity (allowing some leeway for atmospheric drag) without sterilizing it first. For a microbe that is stable at 114degC (the last record-breaking temperature I heard of for metabolism) and 30MPa confining pressure, the problem is less one of getting it to escape velocity (plus...) without overcooking it, but of getting it from 30MPa confining pressure to zero without rupturing every cell.

Hmmm, I have a thought experiment in mind, which I could potentially perform without buying any (new) fancy kit. I vent one of my 300bar diving gas bottles to atmosphere, pour a litre of home brew beer-making kit into the 7l bottle, then equalise ("decant") between that and my 12l bottle. That would, I calculate, give balanced bottles at 189.84 bar. Take the 12l bottle down to the shop for a refill, and decant again for 259.42 bar. Third decant, 285 bar. 6th decant takes it to over 299 bar, assuming that I really get 300bar fills (I don't; rarely better than 270bar).

Then, after slowly ramping the pressure over several days, I vent the pressure over a period of seconds. Drain the brew off, and see if the bugs have survived. Anyway ; that's a doable experiment. Except that I'd have to pay to have the tank serviced afterwards.

Would the bugs survive? Maybe. But that is just one aspect of the things that these putative panspermia microbes would have to survive.

Endoliths are quite tough organisms, well adapted to cold and water stress. They avoid having to handle UV radiation by burrowing into intergranular pore spaces in the rocks. So by definition they are in pressure communication with the atmosphere (from which they acquire CO2 and water). That doesn't mean that they're well adapted to surviving against vacuum, and they have precisely one generation and probably only a few hours to get it right first time.

I think panspermia is an interesting idea, but it is intellectually unsatisfying because all it does is move the hard question - of the origin of life from non-life - from here to somewhere else. It doesn't actually answer the question, any more than a loan from a loan shark solves the problem of too much spending and not enough income.

so chicxulub was casued by a monolith

[Anonymous Coward]

So is this conclusive proof that Chicxulub was caused by a monolith impact? Or do we need to find middle american civilization references to spacemen ?

Re:so chicxulub was casued by a monolith

[Anonymous Coward]

Or do we need to find middle american civilization references to spacemen ?

Would You Like To Know More?

If we find it, the obvious tests

[JoshuaZ]

At this point, we have a pretty good understanding of using genetics to estimate roughly when two populations diverged. If we find such life, we can first test if it at all resembles Earth life. If it does (in the sense that it uses most of the same amino acids, and uses similar machinery for DNA and replicating DNA), then we should be able to get a rough estimate of when it separated from Earth life based on how genetically different it is. There will be some difficulty with this sort of technique, since the life on alien worlds may be subject to extreme selection pressures, but that should be something we can roughly account for.

Re:If we find it, the obvious tests

[i kan reed]

Well, yes and no. The genetic drift measurements we use depend on a relatively consistent rate of selection. A few generations in a hyper-extreme environment, with lots of territory and niches to gain, and lots of extinction potential might happen at a substantially faster and less predictable rate. Especially since extreme environments have been shown to affect mutation rate.

Re:If we find it, the obvious tests

[Anonymous Coward]

The more obvious test would be if it tastes like chicken.

Re:If we find it, the obvious tests

[Anonymous Coward]

> If we find such life, we can first test if it at all resembles Earth life
Not if they test us first!

Re:If we find it, the obvious tests

[jrumney]

I wouldn't want to be the one who was assigned to take samples if this life turns out to resemble velociraptors.

incorrect!

[Anonymous Coward]

jesus was the one who liberated the dinosaurs - i have seen pictures of him riding one!

Re:incorrect!

[Anonymous Coward]

jesus was the one who liberated the dinosaurs - i have seen pictures of him riding one!

What ignorance. The dinosaurs were killed during the global flood. They couldn't fit in Noah's Ark.

Re: incorrect!

[Anonymous Coward]

Actually, if evidence that dna is on other planets and if we find life on other planets with DNA, I would think that would actually give believers more reason to believe - GOD's Fingerprint is on it!

Then again, the Fundies will still clutch to their Bibles say that life was placed there by the Devil. I know, I come from a Fundamentalist family.

Re:incorrect!

[viperidaenz]

They're in magical fairy la.... I mean heaven.

Re: incorrect!

[pollarda]

I have always found it interesting that people take a 2,000 page book and insist that they can read how God accomplished just about everything. This is especially the case when it takes isles and isles of documentation to describe just about anything complex. I have a sneaking suspicion that when we die and get to the pearly gates (or not) and find out if there is an afterlife (or not) that we will find out how little we really know and how childish our interpretations really were.

Re: incorrect!

[Anonymous Coward]

Ask your fundie parents where in the Bible it says God isn't allowed to create life elsewhere.

Re: incorrect!

[SJHillman]

So what you're saying is that, should religion pan out, it's the ultimate example of the Dunning–Kruger effect?

Re:incorrect!

[TheCarp]

Nuh uh. Animals don't have souls[1]

[1] Ref 1989 - Confraternity of Christian Doctrine class - incidentally the very topic that convinced me finally that "they just made all this up", and convinced me, much to my mother's dismay, that I was done with CCD and religion.

Re: incorrect!

[Anonymous Coward]

My family believes that the Bible IS the word of God. I once suggested that maybe when God "wrote" it he was just trying to communicate with a prescience society and that it should be taken with a grain of salt.

Yep, nope!

Re: incorrect!

[ColdWetDog]

"isles and isles of documentation"

So you are saying that somewhere, in some distant and unexplored ocean there are islands filed with mouldering ancient texts that explain the origin of life, the universe and everything? Fascinating.

Have you considered pitching this idea to a video game company?

Re: incorrect!

[Anonymous Coward]

I think you completely missed the point. Try reading the post again a couple of times.

Re: incorrect!

[Runaway1956]

Good question. One which few people will even touch. Fact is - there is no such restriction. If a God or gods meddled in life here, they had all the same reasons to plant life hundreds, thousands, millions, or quintillions more times around the universe. One of the crazier stories I read in my youth had God and Satan taking turns designing newer and better planets. On this planet, God is the creator, on the next planet, Lucifer is the creator and God is the antagonist.

Re: incorrect!

[icebike]

I'm sure the point was not missed.

But I'm also sure the misspelling grabbed ColdWetDog's eyeballs and bitchslapped them so hard that was necessary to triple read the post just to extract any meaning, while at the same time choking back a guffaw.

Re:incorrect!

[laie_techie]

Nuh uh. Animals don't have souls[1]

[1] Ref 1989 - Confraternity of Christian Doctrine class - incidentally the very topic that convinced me finally that "they just made all this up", and convinced me, much to my mother's dismay, that I was done with CCD and religion.

No single person or organization speaks for all of Christianity. There are thousands of sects divided into hundreds of denominations. And why is Christianity divided? Because they don't agree on how to interpret the Scriptures.

Re:incorrect!

[Anonymous Coward]

You were allowed to quit CCD? Lucky fuck. Man, did I hate that shit.......

Re:incorrect!

[Anonymous Coward]

I too believe that Charge Coupled Devices and religion do not mix. All hail the separation of electronics and theology!

Re:incorrect!

[richlv]

that sounds like no true scotsman, just on a larger scale

Re: incorrect!

[LynnwoodRooster]

I have always found it interesting that people take a 2,000 page book

Mine is on a really long scroll as originally created, you insensitive clod!

Re: incorrect!

[Anonymous Coward]

http://www.merriam-webster.com/dictionary/isle
http://www.merriam-webster.com/dictionary/aisle

Re:incorrect!

[Zordak]

It's really more of an inverse "no true Scotsman." There are plenty of people who claim "No true Christian believes X, because Christianity is defined [by me] as people who believe Y." But the GP's thesis was that "Different flavors of Christianity believe everything from A to Z." If you define "Christianity" broadly as "people who believe in the New Testament," you will find a great deal of variance.

Re:incorrect!

[TheCarp]

And yet....all united under the single fact that they.... just made it all up.

Re:incorrect!

[laie_techie]

It's really more of an inverse "no true Scotsman." There are plenty of people who claim "No true Christian believes X, because Christianity is defined [by me] as people who believe Y." But the GP's thesis was that "Different flavors of Christianity believe everything from A to Z." If you define "Christianity" broadly as "people who believe in the New Testament," you will find a great deal of variance.

Bingo! The term Christian is too broad to imply much of anything. Individual sects within Christianity may apply "no true Scotsman", each claiming to be the only true Christians.

I can speak with authority on what my sect believes, but for every doctrine you will find at least 20% of other sects will disagree on any given point. Six literal 24-hour periods in the Creation or was this a complex story expressed in a way that man could understand it way back when? Sola scriptura, or are modern prophets allowed? Is baptism required, or just an outward sign? Should baptism be by sprinkling or immersion? Was the flood truly universal - covering all dry land on the planet, or was it a localized flood just covering that land (a la Atlantis)? Did the flood last a literal forty days and forty nights, or is this a case where the Jews used the number forty to mean "a lot"?

For what it's worth, my sect believes that all animals have souls.

Re:incorrect!

[TheCarp]

> For what it's worth, my sect believes that all animals have souls.

Of course but, it was never about the specific belief as much as, the inconsistency of it... they are made of the same stuff as us, with similar organs, similar genetics, even the ability to learn and adapt (to varying degrees)... so this idea that there is some "soul" that we have and they don't just well... it seemed to not be based on anything but somebodies imagination.

If a soul exists, then we should be able to come to some objective agreement about what it is and how to measure it; which doesn't leave much room for both the soul mapping to something real and the existence of so many sects.

Now of course, this is my view after 20ish years later, but even at the time it was pretty obvious that these ideas came from people's imaginations.

Re:incorrect!

[TheCarp]

Aum's Law?

Re:incorrect!

[laie_techie]

Most religious and spiritual matters can't be empirically or objectively measured. In the Hawaiian mythos, the soul is called "ha" (the breath of life). This is the same "ha" found in the words "Hawaii" (breath of life in the waters), "aloha" (may the divine breathe a blessing upon thy face), and "haoli" (without breath / without a soul). The Book of Genesis says that God gave Adam the breath of life, and he (Adam) became a living soul. I'm not sure we could come up with a definition of soul that all Christians would agree upon. It is a fuzzy concept which normally includes the non-tangible part of ourselves (such as personality, knowledge, ethics) which survives after the physical body dies. How can you objectively measure that? How could you set up an experiment using the scientific method (reproducibility is paramount) to see if humans and / or animals have such a soul? I use science for other parts of my life. I research the best dietary supplements, cars, computers, even the best cloth for my clothes. The programs I write for work certainly aren't faith based. When it comes to religion, though, I go off of what best meshes with my experiences.

Re: incorrect!

[vandamme]

What if on the "seventh day" (the last 13 billion years or so) God rested, seeing that what He created was pretty good already, so He didn't need to mess with it? I know that would throw off some fundamental Protestant timekeeping theories, but Catholics are cool with it.

Would not survive

[Anonymous Coward]

Dinosaurs were adapted very well of a N2 / O2 atmosphere and would not survive very well in the atmospheric mix of Europa or Titan, even if they did survive the journey there in their adult or larval stages. Aside from that, they need a very specific diet to survive that would not exist on any of the moons or planets they might find themselves on after re-entry. To the best of our knowledge, photosynthesis occurs on only a single body in the Solar System - Earth. We would be able to spot it's telltale signs if it occurred elsewhere.

Re:Would not survive

[dreamchaser]

Is that a bad attempt at a joke or did you just miss the obvious? The Earth was teeming with microbial life, some of which could quite possibly endure not just the trip but some of the conditions found elsewhere.

Re:Would not survive

[ganjadude]

I am pretty sure that the article was not referring to the rock being blasted out there with little baby dinosaurs hitching a ride, more like virii and bacterium, and other single celled organisms. but in typical /. fashion I did not RTFA so maybe im wrong and maybe they are talking about t rex and stegosaurus chillin on the moons of Jupiter

Re:Would not survive

[SJHillman]

Fun fact: Evidence suggests that life was around on Earth for some 200 million years before photosynthesis; Even after the evolution of photosynthesis, it would have likely taken millions more years for it to change the atmosphere in any way detectable to visitors... nevermind distant observers. Although its presence may be a telltale sign of life, the absence of it shouldn't be taken as evidence of no life.

Re:Would not survive

[ColdWetDog]

But I like the idea of a 'larval' T. Rex falling down on some foreign planet or moon and reproducing. Jurassic Park in Space?

No, no Mr. Spielberg, that was a joke. Please don't do that. Don't write that down.

Re:Would not survive

[Anonymous Coward]

Ah, but maybe the ejecta carried ghosts of the dinosaurs to a distant planet, and the creepily stiff dead-eyed inhabitants of that world fought a desperate battle against them!

Then they had to collect seven spirits or something, I don't remember.

Re:Would not survive

[Anonymous Coward]

. . . more like virii and bacterium

Every time someone says virii, Daniel Webster kicks a puppy, and when they say bacterium in place of bacteria, he beats his wife.

Re:Would not survive

[camperdave]

Well, no one is saying that the dinosaurs didn't have space travel.

Re:Would not survive

[Opyros]

In that case, I hate to think what Noah Webster does.

Re:Would not survive

[LynnwoodRooster]

It does explain Jar Jar Binks...

Re:Would not survive

[michelcolman]

Well, science has shown that dino DNA in amber has degraded so much that it would be impossible to create a real Jurassic Park with it. However, DNA on a rock that flew into space and stayed at very low temperatures might give better results, right? So they could come up with a scenario in which a space ship flies to Titan, finds a rock containing dino DNA, incubates it into a real life T-rex on board the ship, etcetera. It will be unlike any movie ever done before!

Chigs!

[wang620]

Watch out for Chiggie von Richthofen...

Re:Chigs!

[perpenso]

Watch out for Chiggie von Richthofen...

He's unrelated. 65 million year old Mexican rocks are still traveling to his home world.

That said, an amazingly good show for broadcast tv, of course it didn't last.

Re:Chigs!

[mmell]

Yup. Doomed to fail. It aired on FOX.

Re:Chigs!

[Anonymous Coward]

It was depressing as hell though. Every single episode was dark, grimy, sad, depressing. They should have called it "Emo, watch me cry!" This made it very hard to watch.

Re:Chigs!

[mmell]

The shows protagonists were a group of young, untried Marines earning their hash-marks during an unexpected (and punishing) war. Several dark and highly controversial issues and themes were explored during the show's brief run. Yes, it's dark, grimy, sad - if you were expecting comedy and lighthearted entertainment, perhaps you should stick with "Friends".

Re:Chigs!

[Anonymous Coward]

Yup. Doomed to fail. It aired on FOX.

Not doomed to fail, doomed to be canceled and possibly picked up by another network.

Re:Chigs!

[Anonymous Coward]

It was depressing as hell though. Every single episode was dark, grimy, sad, depressing.

True, yet a less sanitized depiction of combat (casualties were not limited to anonymous redshirts) on broadcast tv was refreshing. I tuned in each week partly because of this, curious to see how far they would depart from traditional tv this week.It was also interesting to see some real moral issues being discussed. Plus space marines, dogfights and explosions.

Re:Chigs!

[perpenso]

A cable channel (don't remember which) apparently got the rights to run a marathon, they even showed the final episode(s) that never made it to broadcast TV. As fitting this show, no happy ending.

Great movie title: Dinosaurs in Space

[Anonymous Coward]

And scientifically plausible too!

Re:Great movie title: Dinosaurs in Space

[laie_techie]

There was actually a Doctor Who episode about Dinosaurs in Space.

Re:Great movie title: Dinosaurs in Space

[Zordak]

No, there wasn't. But there was this one time when some 13-year-old kids somehow convinced Matt Smith to stand in front of their camera for a few minutes, and then they used MS Paint to put some dinosaurs in the frame and somehow convinced people it was an episode of Doctor Who. (It's a well-known phenomenon, actually, called the "Star Trek V Effect.")

Re:Great movie title: Dinosaurs in Space

[Anonymous Coward]

http://en.wikipedia.org/wiki/Dinosaurs_on_a_Spaceship

I only just watched this episode last week as ABC is doing a episode a day of at least the last 2-3 seasons of Dr Who in the leadup to the new special next week...

Re:Great movie title: Dinosaurs in Space

[laie_techie]

http://en.wikipedia.org/wiki/Dinosaurs_on_a_Spaceship

I only just watched this episode last week as ABC is doing a episode a day of at least the last 2-3 seasons of Dr Who in the leadup to the new special next week...

Ah, sorry, I go the name wrong. Of course it was Dinosaurs on a Spaceship (much better than Snakes on a Plane, FWIW). A bit silly, but most episodes of the Doctor are.

I for one...

[roc97007]

...welcome our new Sleestak....

Sorry, I can't go on.

seems extremely unlikely

[epyT-R]

At the point of impact, aren't we're talking millions of degrees of heat energy? Wouldn't this sterilize anything ejected from the planet?. This whole premise sounds more like a bad scifi movie than a real hypothesis.

Re:seems extremely unlikely

[Anonymous Coward]

It is a real hypothesis. It's just not a theory, due to lack of evidence.

Re:seems extremely unlikely

[MozeeToby]

Rock is a pretty good insulator and the impact would have thrown boulders from well away from ground zero. Basically, you've got a single shot Orion Drive with rock instead of a steal shield. You'd actually have a harder time keeping a rock cool on the way up and out than from heat directly from the blast; you'd have to leave the ground significantly above escape velocity to maintain that speed through a few dozen kilometers of atmosphere.

Re:seems extremely unlikely

[Anonymous Coward]

As stated in the summary, these are the conclusions of a model determining roughly how much rock would be launched into space without surpassing 100 degrees C, and in large enough chunks that some of the core should be well shielded from hazardous radiation.

Re:seems extremely unlikely

[Anonymous Coward]

At the point of impact, aren't we're talking millions of degrees of heat energy? Wouldn't this sterilize anything ejected from the planet?. This whole premise sounds more like a bad scifi movie than a real hypothesis.

Let's see, summary says: "70,000,000,000kg ejected[...] 20,000kg hit Europa, and one or two rocks probably bore life" Yeah, one or two out of a million rocks fits the definition of "extremely unlikely", but lucky for those microbes, they had a million tries.

Re:seems extremely unlikely

[Anonymous Coward]

Depends, thermal conductance matters a LOT. If the heat is applied quick enough to a large enough rock then you can end up with only enough energy into the rock to scorch the outside (only the parts in contact with the high heat actually get hot), the inside might warm up but never get hot. You get a similar effect with the laser facelifts, enough heat is applied to vaporize and remove skin, but it's applied quickly enough that you don't get a significant burn, however 150'F water can cook your hand through while leaving much of your skin intact if you happen to leave you hand there long enough.

Re:seems extremely unlikely

[Anonymous Coward]

There's a big difference between "point of impact" and "edge of the blast zone where there's still enough energy to hit escape velocity". A couple hundred miles, in this case. Not to mention the thickness of the rock being ejected, which is only heated on the surface.

This has been analyzed and discussed for over a decade. Do try to keep up.

Re:seems extremely unlikely

[gman003]

Not really.

Asteroids hit the ground at about room temperature on the surface, and often below ambient temperature internally. Anything being blasted into orbit would experience similar temperature increases on the way out.

The spot directly impacted would be heated considerably, but the crater would extend many miles beyond that. I find it entirely feasible that such "life-bearing" rocks could exist.

What I find less likely are the odds of these rocks being blasted well out of Earth orbit, and impacting another planet or moon. The delta-e between Earth and Mars, let alone Earth and Europa, is pretty significant, and more importantly, space is really goddamn big. Yet even that stands up, under further consideration. They're claiming only 3 parts in a million hit Europa, which seems reasonable. I would expect far more rocks to have hit Mars or particularly the Moon, which brings up some interesting questions.

Re:seems extremely unlikely

[Runaway1956]

Just for the sake of argument - an impact that size, ejecting one or more huge fragments of the earth's crust, would necessarily rip the atmosphere apart pretty thoroughly as well. Smaller fragments of the earth's crust might follow behind a large fragment, travelling in a near vacuum. We could probably model some of those rocks escaping the atmosphere without being heated enough to be sterilized. I put this in the realm of possibility, but I don't put it high in the realm of probability.

Re:seems extremely unlikely

[ZombieBraintrust]

Rocks burn up falling through atmosphere. Were talking about accelerating a rock upwards from the ground through the same air into space.

Re:seems extremely unlikely

[c0lo]

At the point of impact, aren't we're talking millions of degrees of heat energy? Wouldn't this sterilize anything ejected from the planet?.

Taking into account the speed of heat diffusion in the mass of the ejecta, it may happen that the surface may reach some thousands degrees without the core experiencing an increased temperature of more that some degrees. I'd say, within the realm of possible for a rock 3 meters in diameter, ejected at high speed into the near 0K of the space in a matter of seconds.

(don't forget that the impact energy is not transferred in full to a small amount of rock, a big part of it is spent in dislocating those rock and transferring a good deal of kinetic energy. If it helps, think of the Gambaku dome, which was not melted despite being only 160 m from the hypocentre of the atomic explosion)

Re:seems extremely unlikely

[Deadstick]

Objects heat up when they pass through air, period. The rate of heating depends on the air density and the relative speed -- it doesn't care a fig what direction the object is going.

Re:seems extremely unlikely

[painandgreed]

Rocks burn up falling through atmosphere. Were talking about accelerating a rock upwards from the ground through the same air into space.

Rocks burn up in the atmosphere because of the large delta-v between them and the earth. Something falling straight down as if dropped would not have this issue any more than the guy that jumped from space. Escape velocity for the Earth is 11 kms and 42 for the solar system. Unsure what that would look like but given the case, the sample in question would not be shot like out of a gun through atmosphere but likely pushed out by a pressure wave along with everything including the atmosphere around it at the same time. It would be subject to some serious Gs and perhaps compression, but friction with things around it probably wouldn't be an issue as everything in the vicinity would be traveling in the same direction at the same speed.

Cthulhu did it. I was there.

[madmarcel]

For some reason I read that as:
"Cthulhu Might Have Spread Life Through the Solar System"

to which the answer is: Probably not.

Re:Cthulhu did it. I was there.

[Anonymous Coward]

For some reason I read that as

Yeah, well we really don't care if you can't read.

Earthlings...

[Jedi Holocron]

...polluting space for aeons...

Re:Earthlings...

[symbolset]

Life is absurdly contagious.

Re:Earthlings...

[Lightning McQueen]

This! There's so much junk in space it's like you don't have to worry if your ship breaks down. Find an old 1960's version of your broken part floating around (probably be within 10 feet of you) pop it in and your good to go.

Here you go...

[denzacar]

http://www.youtube.com/watch?v=OjuptfaTqyo

http://en.memory-alpha.org/wiki/Distant_Origin_(episode)

Attempt No Landing There

[tverbeek]

The Sentinel is going to be pissed that we'd already contaminated Europa.

Europa

[foobar bazbot]

Land or land not; there is no attempt.

Amazingly Earth-centric viewpoint...

[dtjohnson]

Imagining that all life must have originated from Earth is an amazingly earth-centric point of view that is similar to the idea in the middle ages that all planets must revolve around the Earth. Obviously, if life can travel from Earth to Europa, it can also travel from Europa to Earth...or from planets outside of our solar system entirely. Moreover, the fossil record shows the presence of life on a very early Earth, leaving far too little time for life to form in primordial Earth oceans under any sort of process currently envisioned. Not only is pan-spermia possible, it is currently the most likely explanation for the source of life on Earth. The real question is 'where did life originate in the universe?'

Re:Amazingly Earth-centric viewpoint...

[hubie]

Imagining that all life must have originated from Earth is an amazingly earth-centric point of view

This claim is not made anywhere in the paper, or anywhere else for that matter that I can find.

Re:Amazingly Earth-centric viewpoint...

[Livius]

They're saying this could have been an opportunity for life to migrate from Earth to Europa etc., not that it was the only possible way for there be life there.

Re:Amazingly Earth-centric viewpoint...

[Hatta]

leaving far too little time for life to form in primordial Earth oceans under any sort of process currently envisioned.

While any of the individual chemical reactions required for abiogenesis would be exceedingly rare, you have to consider that they were taking place in parallel across the surface of the Earth. The Miller-Uray experiment ran for a week in a few small flasks. You can expect much less frequent reactions to happen, at least once, when you do the same thing in the entire volume of the oceans over the course of 100 million years.

Re:Amazingly Earth-centric viewpoint...

[VortexCortex]

The real question is 'where did life originate in the universe?'

The conservative answer would be: On the inside.
A liberal answer would be: Anywhere shit has happened.
Like any discovery, information, or idea: Life could have more than one independent origin.
Ergo: All of our patents infringe extraterrestrial prior art.

Re:Amazingly Earth-centric viewpoint...

[RespekMyAthorati]

The Miller-Uray experiment showed basically nothing.

Only simple amino acids were produced, and had they been formed outside of a laboratory,
they would have immediately begun to decompose back into the original chemicals.
This cycle would have repeated endlessly.

How they went on to form the more and more complex molecules needed for life is still unknown.

Is this pronounced 'chicks lube'?

[fredrated]

Not that I would need any, as a card-carrying geek.

Pretty cool

[GrahamCox]

If it turns out to be true, that would be pretty cool.

But I also hope they've made a better go of it than we have. Could hardly be worse, really.

Re:Pretty cool

[Anonymous Coward]

Could hardly be worse, really.

Go read a history book and see what "could hardly be worse."

Ignorant knee-jerk hyperbole doesn't make you insightful. It makes you a troll.

I think you've missed something . . .

[mmell]

Yon organic matter needn't survive, reproduce and grow - it only needs to introduce the kind of complex organic molecules (amino acids, protiens, etc.) which form the foundation of evolutionary life on this planet. Hell, all the microbes in question (be there one or one million) can die on impact as long as their protiens/nucleic acids etc. remain (even partially) intact. Planetery physics will take care of the rest.

Just don't expect anything familiar to evolve out there.

Re:I think you've missed something . . .

[Sique]

Hm... Madagascar is separated from any other land mass since 150 mio years, and the evolution there, while quite different than in Africa, with almost all species being endemic, is not that different from other continents and islands. There are no different orders of species there, just families and genera are different (and endemic). I don't expect an evolution which lasted only 65 mio years, less than half that of Madagascar, to be radically different.

Re:I think you've missed something . . .

[mmell]

Madagascar is nonetheless subjected to roughly the same atmospheric, radiation, and physical environment as the rest of the Earth (magnetic fields, chemicals, gravitic variations due to the presence of a single large satellite in orbit, tides, etc.). Liquid water is present at the surface, temperatures hover between roughly 275-305K. Atmospheric pressure tends to be something like 1 atmosphere (plus or minus a miniscule fraction).

Just sayin'.

Re:I think you've missed something . . .

[Sique]

If it is much colder (as on Europa or Titan), then the van't Hoff rule just lets us expect the evolution being much slower (about 2-3 times per 10 degrees).

Re:I think you've missed something . . .

[ColdWetDog]

But changing rates changes evolutionary pressures and therefore morphology and organization. So, there may well be other effects than a stochastic slowing process.

Overall, life is going to be constrained by the physics of the organizing molecules - proteins and sugars can only do so much. Other chemistries are certainly possible, but we've yet to see them work.

Re:I think you've missed something . . .

[Anonymous Coward]

"Life" doesn't have to be a complex organism. It can be bacteria etc.

Re:I think you've missed something . . .

[Kongming]

While I will agree that 65 million years is not long in geological time, any novel life forms trying to develop on Earth have to compete for limited resources with existing organisms that are already well-adapted to their environments. It is probably much less likely for some alternative to cellular life as we know it to develop here in parallel with existing life than it is somewhere that we seed a supply of proteins and amino acids and watch to see what happens.

Re:I think you've missed something . . .

[CreatureComfort]

Admit it... You're just REEEEEALLY hoping for space lemurs.

Re:I think you've missed something . . .

[bluegutang]

In a sea full of amino acids, you can perhaps expect proteins and life to evolve. But the quantity of proteins transmitted by a few bacteria is miniscule, and if the bacteria died, the amount wouldn't increase. No life could evolve except in the immediate vicinity of those bacteria, and the chances of that are extremely low.

Re:I think you've missed something . . .

[Sique]

No. I just don't expect anything.

Panspermia is some idea that pops up here and there, but I guess it totally misses the point.

• Organic compounds can form in abionic environments. So the null hypothesis should always be: Organic matter has formed where we found it.
• Organic compounds are quite sensitive to high temperatures and get destroyed easily. Most of them burn or at least denaturate. Complex molecules are much more sensitive. A meteor impact will destroy almost all organic compounds but the simplest ones, and those form easily anyway.
• To leave the Earth, the thrown out matter has to have a speed of at least 11.2 meters per second, and this means that air friction will heat the matter, making charcoal out of about every organic matter that happens to be thrown into space.
• Wherever organic compounds are getting to, we can be sure that either they don't survive for long, or that the place already has its own share of organic compounds. The few newly arriving molecules don't really change anything.

Re:I think you've missed something . . .

[Agent0013]

To leave the Earth, the thrown out matter has to have a speed of at least 11.2 meters per second, and this means that air friction will heat the matter, making charcoal out of about every organic matter that happens to be thrown into space.

Ahhh! So that's why we have not been able to get any organic matter into space yet. It keeps burning up in the rockets we send! Maybe someday we can put enough material around it to form some sort of heat sheild? What do you think, would that work?

Yay!

[Anonymous Coward]

Dinosaurs on Europa!

There's no Vise, and no Versa either!

[TapeCutter]

Earth is still throwing rocks into space in modern times, a significant portion of what was once the island of Krakatoa is now in space. The force of the explosion is said to have shot rocks the size of houses into space.

As for seeding the solar system I personally think it's possible but improbable due to the fact that when a space rock hits a planet or moon at that speed, it is instantly vaporised and then rains down on the surface as microscopic glass beads, if it survives that then it's certainly comes under the heading of "Life - but not as we know it".

Life is a natural phenomena, it's chemistry that talks, like volcanos or any other natural phenomena life will emerge when and where the conditions are right for it to do so, for example the conditions on Mars may once have been right for life to emerge, but a thunderstorm will never emerge under the current conditions. Science is now pretty confident that one place where conditions are right for life to emerge are deep sea vents. So sure, the Earth might sneeze it's germs on other planetary bodies, but if those germs are to survive they will need to find the conditions where life can emerge and survive anyway.

The whole binary debate around panspermia is missing the point entirely, any sizeable and 'watery' rock floating in space, be it a planet, moon, comet will probably have some indications of microbial life either past or present. In fact the people who came up with the panspermia concept think that the idea of a unique point in space and time for life to emerge is just silly, panspermia is more analogous to pollen floating through a field of wheat, the point being that the wheat itself is created from countless seeds.

Re:There's no Vise, and no Versa either!

[Deadstick]

Earth is still throwing rocks into space in modern times, a significant portion of what was once the island of Krakatoa is now in space.

Cite? Throwing rocks into space is one thing; throwing them so they don't come back is quite another. Absent an injection thruster that kicks in at the right height, the only way to prevent an object coming back down is to accelerate it to escape velocity. That's a tall order.

Re:There's no Vise, and no Versa either!

[able1234au]

>it is instantly vaporised and then rains down on the surface as microscopic glass beads

So no meteorites have landed on earth?

Re:There's no Vise, and no Versa either!

[Anonymous Coward]

>it is instantly vaporised and then rains down on the surface as microscopic glass beads

So no meteorites have landed on earth?

Bingo!

Hooray!!!

[frank_adrian314159]

Dinosaurs on Europa! We should go there, bring a couple of 'em back, and open a theme park! I'll call it "Jurassic Park XIV: The End of the World"!

Sample rocks on the moon

[sinequonon]

Samples of such rocks may still be in lying pristine condition on the Moon. Their DNA won't have survived due to cosmic ray bombardment, but we may still find interesting information about early life. One day we'll send a robotic surface explorer to look... I hope.

Table 5

[ZombieBraintrust]

The 20,000kg number is from Table 5 in the journal. I think the summary is a little deceptive.
Probablilty of life bearing rock ejected from earth reaches Europa is: 2.8E-6 ± 5.0E-7 %
Yeah thats .0000028% plus or minus .0000005%
Including all rocks that were ejected they believe 6 plus or minus .9 rocks would reach Europa.
The 20,000 Kg number comes from those 5 to 7 rocks.

Re:Table 5

[fatphil]

Can't be arsed to work out solid angles in steradians, let's just do things in terms of area, as all that matters is the ratio.

Area of the earth: 5*10^14 m^2
Area of projection of Europa onto earth's surface: 5*10^2 m^2 ( http://xkcd.com/1276/ )
=> Ratio of "out there" which is Europa: 10^-12.

I would therefore claim that unless there's a bloody good reason for things to be 30000 times larger, the probability of ejecta reaching Europa should be more like 0.0000000001%

And that presumes nothing in between us and Europa sweeps it up (such as a gravitational well such as the sun, or jupiter).

Re:Table 5

[fatphil]

OK, now I'll look at the paper....

The simulation makes steps that are 1 day in granularity.
They are simulating particles that are travelling 10km/s.
Therefore one time step is 10^6 km.

They are asserting that these objects that take million kilometer steps are intersecting with a 3000km target which is also moving a million kilometers per day (relative to jupiter, sometimes twice that, sometimes half that relative to the sun). I would suggest that they are grossly overestimating the probability of collision in that case. I have performed orbital simulations myself, and noticed that anything that involved close approaches required massively higher precision (not just shorter time steps, I had to find significantly more stable algorithms). Every time I increased accuracy, the number of collisions and of slingshots-into-infinity decreased by orders of magnitude.

They should log the initial conditions of one Europa-impinger, and then just re-run the simulation with far smaller time steps (e.g. ones which cause things only to move 1000km, rather than 1000000km per unit time), and with a range of perturbations about that "hit" (which isn't as expensive as it sounds, it's only when div starts to get high that you need to do more than just one simulation plus offsets in 2 dimentions.

According to their table 4, we've received 70000kg of solid matter from mars in the last 35 years. Can they identify any of that matter, I don't remember seeing any stories of such great quantities arriving?

The Ioans are laughing at us.

[140Mandak262Jamuna]

Scientists at Ioan Space Agency are laughing at earth for lobbing back a few rocks with primitive life forms in them back it Io. They point out that it originally the ejecta from Io that actually seeded the biology of Earth.

Re:The Ioans are laughing at us.

[VortexCortex]

Scientists at Ioan Space Agency are laughing at earth for lobbing back a few rocks with primitive life forms in them back it Io.

Thus, lo and beheld was the veracity of loan sharks.

Well played, sir. I stand corrected.

[mmell]

Actually, SAAB and B5 are two oldies I'd really like to see "rebooted" or even "reimagined".

Moon rocked

[hcs_$reboot]

The Moon side facing us (unlike the other side) is riddled with craters that may have appeared around that time (~-65My). A big chunk of the ejected rocks on Earth may simply have landed on the Moon.

Seed other planets

[Anonymous Coward]

Why don't we get over the fact that life does not exist on other planets and start seeding planets with extremophiles?

65 Million years is long enough ...

[Ihlosi]

... to cross interstellar distances even at ridiculously low velocities. Something travelling at less than 100 m/s will travel over ten light years in 65 million years. Chunks from Earth might have ended up in the Alpha Centauri system by now.

Btw, have we found any extrasolar debris in our star system? It might be like looking for a needle in a haystack, but I'm sure we could find some pieces of exoplanets right in our back yard.

Typical

[ThatsNotPudding]

It had to be called panspermia, not panovumia, right? Right.

Latest news!

[Anonymous Coward]

Dinosaur shit encountered on Pluto's crust.

Hooray, another unlikely story from space!

[badasawsomeness]

I love theoretical physics and all the crazy ET stories as much as the next guy. However, it can be taken to the point where no one cares. Seriously reading a story that basically said, a meteor crash had a 20% chance to send a large rock in to space, with a 10% chance that contained some bacterial form of life, that had a 5% chance of surviving the heat and extreme atmosphere changes going in to space, leading to a 1% chance it would then survive hundreds of years flying through a cold radiation filled vacuum, leading to the .00001% chance that it hit a moon that might be able to support some form of life.

And say this far fetched story actually happened, what is the amazing result that awaits us when we reach said moon!? An undetectable amount of frozen bacteria that went on a $h**ty space adventure and crashed in to a lifeless moon and died soon after.

If you are going to have a crazy unlikely story of how a ridiculous chain of events helped life travel through space, at least make up an interesting ending.

Re:Hooray, another unlikely story from space!

[vandamme]

Well, the moon used to be made of green cheese, but by 1969 it had died off.

obligatory

[Anonymous Coward]

I for one, welcome our new Europan dinosaur overlords!

that was epic.

[WittyName]

A work of art. Up there with Tolkien. Beautiful use of language.