Meteorites might have spiked up Earths primordial soupMarch 14th, 2008 - 1:21 pm ICT by admin
Washington, March 14 (ANI): Scientists have discovered concentrations of amino acids in two meteorites that are more than ten times higher than levels previously measured in other similar meteorites, which suggests that these space objects are a rich source of primordial soup, which might have helped in life formation on Earth.
The study, carried out by Marilyn Fogel and Conel Alexander from the Carnegie Institution, with Zita Martins of Imperial College London, also suggests that the early solar system was far richer in the organic building blocks of life than previously thought.
Amino acids are organic molecules that form the backbone of proteins, which in turn build many of the structures and drive many of the chemical reactions inside living cells. The production of proteins is believed to constitute one of the first steps in the emergence of life.
Scientists have determined that amino acids could also have formed in some environments on the early Earth, but the presence of these compounds in certain meteorites has led many researchers to look to space as a source.
Now, the researchers, for their amino acid study, took small samples from three meteorites of a rare type called CR chondrites, thought to contain the oldest and the most primitive organic materials found in meteorites.
The meteorites used for the study, were collected in Antarctica in 1992 and 1995.
The analysis revealed that while one sample showed a relatively low abundance of amino acids, the other two meteorites had the highest ever seen in primitive meteorites180 and 249 ppm (parts per million).
Because organic molecules from extra-terrestrial sources have ratios of carbon isotopes different from those of Earthly biological sources, the researchers were able to rule out contamination as a factor in their result.
According to Alexander, the amino acids probably formed within the parent body before it broke up.
For instance, ammonia and other chemical precursors from the solar nebula, or even the interstellar medium, could have combined in the presence of water to make the amino acids. Then, after the break up, some of the fragments could have showered down onto the Earth and the other terrestrial planets, he said.
These same precursors are likely to have been present in other primitive bodies, such as comets, that were also raining material onto the early Earth,” he added. (ANI)
Tags: amino acids, biological sources, carbon isotopes, carnegie institution, chondrites, conel, early earth, early solar system, emergence of life, fogel, imperial college london, life scientists, meteorites, organic materials, organic molecules, ppm parts per million, primordial soup, rare type, space objects, terrestrial sources