NASA Discovers Life's Building Block In Comet 148
xp65 writes "NASA scientists have discovered glycine, a fundamental building block of life, in samples of comet Wild 2 returned by NASA's Stardust spacecraft. 'Glycine is an amino acid used by living organisms to make proteins, and this is the first time an amino acid has been found in a comet,' said Jamie Elsila of NASA's Goddard Space Flight Center in Greenbelt, Md. 'Our discovery supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts.'"
Tin Foil Hat (Score:3, Interesting)
It also supports the theory that some other planet full of life went *KA-BOOOM*
Aliens of said planet are now patrolling the galaxy looking for the next M class planet to colonize.
Stuff != life (Score:5, Interesting)
Um... it didn't. "Building blocks for life" does not equal "life". But once the 'building blocks' formed, life could get started... almost certainly on Earth. See, e.g., here [discovermagazine.com].
Re:Where did that stuff come from? (Score:4, Interesting)
"What caused the life to form way out there?"
As far as we can tell life didn't form way out there. Just an amino acid fundamental to life. Life as we know it requires liquid water, a certain atmosphere, gravity, and a bunch of other requirements.
"It's fine and dandy to push the building blocks of life off-planet, but how can those blocks then be explained?"
The building blocks for life have to come from somewhere, they don't just appear out of nowhere (or do they?). After all, isn't life really just the combination of left over heavier elements created through exploded stars and other space junk that just happened to end up on earth through meteorites, comets, and the accretion process...
Re:Again? (Score:2, Interesting)
Yeah, and each time, it's obvious the evidence was planted.
I RTFA and tried to figure out how they are 100% certain the glycine is from space. Apparently it's because of the isotope ratios of C12 and C13, with more C13 being present in space. My question is, how much glycine did they collect? The link to the analytics on NASA's website keeps timing out.
Re:How sure? (Score:1, Interesting)
Speaking of which, how much energy would it take to me the entire EARTH a spaceship? Like completely knocking it out of the gravity well of the sun so that we could travel on it to another place. Of course we would have to do something about light for the plants and animals that are living here, but imagine creating a large reflector that we rotated around the entire earth and shine down light transmitted from the ground. We could have an entire planet as a spaceship, which might be useful if this sun starts to blow up on us.
Faulty Logic? (Score:5, Interesting)
"Our discovery supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteorite and comet impacts."
Instead it only supports what Dr. Pilcher says in the article:
"The discovery of glycine in a comet supports the idea that the fundamental building blocks of life are prevalent in space, and strengthens the argument that life in the universe may be common rather than rare."
In other words, it's just saying that amino acids are not that rare. If they're not that rare, why can't Earth have made them on it's own?
After all the Miller/Urey experiment [duke.edu] in 1953 showed that amino acids can be produced fairly easily if a few simple conditions are met.
Miller took molecules which were believed to represent the major components of the early Earth's atmosphere and put them into a closed system
The gases they used were methane (CH4), ammonia (NH3), hydrogen (H2), and water (H2O). Next, he ran a continuous electric current through the system, to simulate lightning storms believed to be common on the early earth. Analysis of the experiment was done by chromotography. At the end of one week, Miller observed that as much as 10-15% of the carbon was now in the form of organic compounds. Two percent of the carbon had formed some of the amino acids which are used to make proteins.
Maybe comets and meteors with amino acids were hitting earth as well. But finding them all over space also strengthens the idea that they're not uncommon to produce, and therefore also strengthens the theory that Earth could have produced them by itself. Either way seems like a guess to me.
Fun fact for the day: The Murchison meteorite [wikipedia.org] which fell in Australia in 1969 also contained common amino acids such as glycine, alanine and glutamic acid as well as unusual ones like isovaline and pseudoleucine.
hypotheses (Score:5, Interesting)
1) it was scooped from earth or another planet with life by the comet: dubious
2) a planet with life somewhere got crushed and the ejected material that formed the comet got some amino acids in it. weakly possible.
3) Given it's been shown that freezing primordial materials found in space actually promotes the formation of nucleic acids, it might not be much of a reach to suppose that there are natural processes in cold space that will form amino acids.
4) there are life forms that live on comets. presumably then panspermia is ubiquitous.
5) the gel got contaminated on earth. or the mass spec is not definitive about the molecule in question.
I lean towards 5, and then 3 as a close second. Of course 4 would be interesting, as it's direct panspermia. But if indeed the building blocks of life as we know it pervade the universe and occur naturally it also suggests there probably are a lot of similar nucloetide/peptide base life forms out there.
Re:How sure? (Score:3, Interesting)
The competitive, and somewhat older, hypotheses were that glycine and other amino acids were formed in primordial tidal pools, or in the atmosphere during lighning storms, and so on. So this finding is significant in demonstrating that at least some amino acids can be formed under extraterrestrial conditions. This weakens the "Earth is a very special place" arguments. So this is a fairly important finding.
Also kudos to the analyst teams for finding ways to handle such small specimens. This result is the product of a technology that could not even be imagined 15 years ago.
A question for anyone who has studied the subject: do we have any idea why there is a difference between terrestrial and extraterrestrial carbon isotope ratios? Or for that matter, the higher presence of iridium in space rocks, etc?
Re:Tin Foil Hat (Score:4, Interesting)
If we can eat, and be nourished by, alien life then any bacterium from the same environment could use US as food as well.
And even then alien predators would likely still TRY to eat us if they thought we might taste good, or could be used as incubators for their parasitic, chest busting, off-spring, or they might just want to hunt us for sport with plasma based weapons while using active-camo.
Re:hypotheses (Score:3, Interesting)
Reproduction would proceed very slowly in interstellar clouds, due to the low density of the gas.
You'd need a planet for the chemistry to proceed at a rapid pace (due to both temperature and density). I'm not saying that the planet has to be Earth, but a planet would be the most likely starting point.