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

[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

[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

[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

[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

[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

[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.

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.

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

[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: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.

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

[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.

Earthlings...

[Jedi Holocron]

...polluting space for aeons...

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.

Attempt No Landing There

[tverbeek]

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

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!

[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.

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.

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.