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NASA Discovers Life's Building Block In Comet
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.'"
"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 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 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.