March 1, 2011

Building Blocks Of Life Could Have Come From Outer Space

Fragments from a meteorite found in the Antarctic strengthen the argument that the elements needed to begin life on earth could have come from outer space, claims a new study published Monday in the journal Proceedings of the Natural Academy of Sciences (PNAS).

In the study, authors from Arizona State University and the University of California, Santa Cruz, analyzed a nearly 4g sample of powder taken from a meteorite known as Grave Nunataks 95229, which according to BBC News Science Reporter Neil Bowdler had been discovered in 1995.

They bombarded those fragments with heat and pressure, Telegraph Science Correspondent Richard Alleyne reported on Tuesday, and by doing so "have recreated conditions at the beginning of life as we know it," he added.

Under those "primordial" conditions, the meteorite emitted ammonia, which Alleyne refers to as "an essential compound in the production of amino acids, the so-called building blocks of life."

After reviewing the nitrogen atoms contained within the ammonia, the scientists were able to dismiss the possibility that their sample had been contaminated, as "the atomic isotope did not match those currently found on Earth," according to the Telegraph.

Carl Holm of ABC News in Australia added that Grave Nunataks 95229 "contains relatively high amounts of ammonia and amino acids," and that the discovery "adds extra impact to the theory that the essential building blocks of life on Earth came from outer space."

Sandra Pizzarello, a professor with the Department of Chemistry and Biochemistry at Arizona State University in Tempe, served as the lead author for the study. Joining her were colleagues Gregory P. Hollanda and Jeffery L. Yargera; Lynda B. Williams from the Tempe university's School of Earth and Space Exploration; and Jennifer Lehman from the Department of Earth and Marine Sciences at the University of California, Santa Cruz.

Pizzarello told Bowdler that their research "shows that there are asteroids out there that when fragmented and become meteorites, could have showered the Earth with an attractive mix of components, including a large amount of ammonia."

"We speculate that their delivery to the early Earth could have fostered prebiotic molecular evolution," the authors added in their study, which is entitled 'Abundant ammonia in primitive asteroids and the case for a possible exobiology.'


On the Net: