Murchison Meteorite Still Contentious

An anonymous reader writes "The well-known 1969 meteorite that fell 60 miles north of Melbourne, Australia, remains remarkably contentious today. The 100 kilogram carbon rock : a) contains pre-biotic proteins and 12% water; b) harbors 50 amino acids not found on Earth; c) favors the tell-tale signature of biochemistry based on a dominant left-handed chirality, compared to random or racemic mixtures found in test-tube syntheses. While terrestrial contamination (even interior to the meteor) may discount this so-called 'Murchison meteor', its light isotopes of carbon and nitrogen suggest the left-handed amino acids not found elsewhere on Earth have the same ratios as the right-handed ones. This would not be the case if, say, bacteria was just making the left-handed ones after impact. Seems quite a controversy from down-under."

Comments

Hmmm

[mao che minh]

"c) favors the tell-tale signature of biochemistry based on a dominant left-handed chirality, compared to random or racemic mixtures found in test-tube syntheses."

.....compared to random or racemic mixtures found in test tubes on Earth. We have yet had no other "lab" from which to study life and it's building blocks (life as we know it: carbon based and mostly made of water). Therefore, the sudden appearence of such components from the stars might very well appear to be "based on dominant left-handed chirality" when compared to the billions-old formula we have here on our planet.

We also don't know how the environment of space will effect amino acids contained in the rock. Since these amino acids (and other material) are foreign, then how do we know that it isn't natural for them to be collected in such a manner?

Never forget the scientific method. You have to ask questions. After you're done asking questions, submit to your peers for them to ask questions.

It really isn't compelling at all. It's similar to how UFOlogists focus on half truths and anamolies that confirm their theories, while ignoring the evidence that shows how 90-95% of all sightings are reasonably explained (the tons of disconfirming evidence). They also turn their nose up to the community and the world, effectively becoming the closed-minded character that they try to call the real scientists: Real scientists submit their work to thousands of peers and accept feedback and analysis. Psuedoscientists do not, and yet they call the critical thinkers that reject their ideas closed-minded.

OK, rant over.

Re:How many times...

[Anonvmous Coward]

"How many times will science have a victory over the church before we can finally kill God for good?"

What victory over the church? Science is good for proving that things exist, but it's not very useful for proving that things don't exist. If you're drawing the conclusion that God doesn't exist by what is or isn't on a meteorite, then you're not using science.

Re:Let me ask this...

[br0ck]

Your idea is a valid one and scientists are currently thinking that the best chance to find life in our solar system will be on Jupitor's moon, Europa. However, it is actually extremely difficult to keep the robot probe itself from carrying contamination since modern electronics can't take the extreme heat needed to kill resilient strains which could possibly destroy any life on that planet. Recently scientists have been putting more effort into trying to figure out how to explore Europa without contamination.

Contamination has already been shown to occur easily. The first Apollo mission found the moon to be sterile, but later Apollo missions found strep bacteria from previous missions. Deeply buried in ancient Antarctic ice, Lake Vostok is an enviroment that is thought to contain ancient life forms, but scientists are reluctant to explore the lake until contamination can be prevented. Bacteria has already been found in drilling to just above the top of the buried lake.

Ugh. News and Science don't Mix well

[EvilTwinSkippy]

The signal to noise ratio in this article was essentially zero.

Fact: the meteorite contains ammino acids, and chirality that is not generally found in terrestrial organisms.

Fact: This meteroite is HEAVILY polluted with terrestrial organic matter.

Conclusion: While ammino acids are generated in space, they seem to mimic the compositions found when we try to synthesize them in the lab.

Aside: You can produce the same results with some methane gas, water vapor, and ionizing radiation.

Move along, no controvesy here.

Re:Ugh. News and Science don't Mix well

[joethebastard]

News and science mix much better if you read the article. Try this:

Fact: the signal to noise ratio would be outside error limits or they wouldn't report it

Fact: there are only two chiralities, and synthesizing them in the lab always makes both. biological syntheses always make just one kind.

Fact: isotopic data was used to ensure that contamination didn't effect this chirality data

Conclusion: Some other process that we didn't know about is going on

Aside: if you're interested in this sort of thing, you should read the article.

Re:Hold on a sec!

[zenyu]

amino acids not found elsewhere on Earth

Read it again, slowly.

It doesn't say "amino acids that do not exist elsewhere on Earth."

Simply that they haven't been found elsewhere, including, I assume, on rocks near the impact crater.