Cometary Impacts May Have Provided Key Elements of Life

trendspotter writes with news of research indicating that impact events might be responsible for seeding the Earth with reactive forms of the precursors to amino acids. From the article: "Early Earth was not very hospitable when it came to jump starting life. In fact, new research shows that life on Earth may have come from out of this world. Lawrence Livermore scientist Nir Goldman and University of Ontario Institute of Technology colleague Isaac Tamblyn (a former LLNL postdoc) found that icy comets that crashed into Earth millions of years ago could have produced life building organic compounds, including the building blocks of proteins and nucleobases pairs of DNA and RNA. Comets contain a variety of simple molecules, such as water, ammonia, methanol and carbon dioxide, and an impact event with a planetary surface would provide an abundant supply of energy to drive chemical reactions." The paper (PDF).

Comments

Comets are nothing but Intergalactic Spermatazoa

[christopher240240]

Panspermia http://blogs.scientificamerican.com/life-unbounded/2012/10/15/the-panspermia-paradox/

Wait, what?

[gstoddart]

Is this even a new idea?

I've heard this for quite some time now, and I thought this was a prevailing understanding.

Re:Wait, what?

[Sockatume]

The idea that comets might be the source of early prebiotic components is old, but this specific research demonstrating that the high pressures and temperatures involved in impacts is capable of converting the simple, common molecules found on comets into more complex prebiotic structures is new.

Re:Wait, what?

[camperdave]

1492...

Guy finds previously unknown land and peoples. No need to follow up.

Guy with terrific PR connections finds "previously unknown land", if you don't count the Vikings, the Chinese, the Japanese, the Polynesians, etc.

Re:Wait, what?

[moeinvt]

Actually, I don't know what's new about this.

http://www.newscientist.com/article/dn16215-meteor-impacts-may-have-sparked-life-on-earth.html

"Yoshihiro Furukawa... used a high-velocity propellant gun to simulate the impacts of ordinary carbon-containing chondrite meteorites .... recovered a variety of organic molecules, including fatty acids, amines, and an amino acid."

There was a multi-part Nova episode called "Origins" where they also demonstrated this. I can't remember the scientist or laboratory, but they put some simple organic compounds inside a metal plug and then fired a high speed projectile into it (or maybe they fired the plug into a target?). When they opened the container, they found that they had created more complex compounds like amino acids. It looked like a translucent liquid at first, and came out looking like dark slime.

Re:Wait, what?

[gstoddart]

if you don't count the Vikings, the Chinese, the Japanese, the Polynesians, etc

Which, oddly enough, they never do.

Much of history boils down to "the world was invented by white Europeans because we wrote the history books".

People tend to downplay just how much stuff we actually knew even 2000 years ago and act like it wasn't there.

Re:Except..

[Samantha Wright]

Well, I for one am extremely unfashionable and actually RTFA:

"The flux of organic matter to Earth via comets and asteroids during periods of heavy bombardment may have been as high as 10 trillion kilograms per year, delivering up to several orders of magnitude greater mass of organics than what likely pre-existed on the planet," Goldman said.

The words "heavy bombardment" have particular meaning in the context of solar system history; the most well-known being the (not quite ubiquitously accepted) Late Heavy Bombardment, on the moon, 4.1–3.8 billion years ago. The bit about "millions of years ago" was probably added by the public relations science writer and should have been "billions." They get this stuff wrong all the time.

Re:commetary life

[wonkey_monkey]

No-one's saying there was life on the comets - just some very useful chemicals.

So 'Gravity is God'...

[starglider29a]

According to Hawking, Gravity (capital G) created the Universe: http://physics.stackexchange.com/questions/13013/stephen-hawking-says-universe-can-create-itself-from-nothing-but-how-exactly
According to TFA, Gravity (capital G) created life (via the kinetic energy of the comets obeying laws of Gravity)
According to Genesis, God created the Universe and life.
Therefore, Gravity = God.

Glad we finally solved that! Can we move on now?

Re:In laymans terms (since I'm a layman)

[Samantha Wright]

You'll have to narrow your scope a little: we're pretty sure that all of the interesting bits of evolution (the distinction between bacteria and archaea, the rise of animals, plants, protists, and fungi, multicellularity, and everything since) happened right here. To use a surprisingly good computing analogy, not only do we have the fossil records, but we can compare the source code and see where the forks happened. A lot of the most interesting adaptations are serendipitous re-uses of really old code.

The possibility that living cells might have arrived on Earth is considered something of a toss-up. There have been quite a lot of difficult-to-test proposals about how they could've arisen from fairly basic building blocks here, and they all seem pretty plausible. We're pretty sure about the RNA world hypothesis (the idea that life only started using proteins for enzymes and DNA for storage later, and started off using just what we think of as a makeshift intermediary for everything) but we don't have much of a clue about what happened before that, and we can't say for certain it happened here or not. We also don't know how life went from being a single self-replicating molecule into a membrane-protected cell, nor if there was some storage molecule before RNA that was even simpler to operate on.

However, this article is almost certainly wrong because RNA's inherent stability causes it to evolve at a much faster rate. So at the very least, it's still possible that there was enough time for life to evolve here from pure abiogenesis.

Re:Except..

[coinreturn]

And billions of years is still millions of years (just more of them).