Showing that the ingredients for life in the universe may be distributed far more widely than previously thought, scientists have found traces of a key building block of biology in dust snatched from the tail of a comet.
Scientists at the Goddard Space Flight Center in Greenbelt, Md., have uncovered glycine, the simplest amino acid and a vital compound necessary for life, in a sample from the comet Wild 2. The sample was captured by NASA's Stardust spacecraft, which dropped it into the Utah desert in 2006.
"By detecting glycine, we now know that comets could have delivered amino acids to the early Earth, contributing to the ingredients that life originated from," said Jamie Elsila, a research scientist at Goddard and coauthor of a paper outlining the discovery in the journal Meteoritics and Planetary Science.
The idea that the ingredients for life were delivered to Earth from space, rather than developing out of Earth's original chemical soup, has been around for years. Amino acids previously have been discovered in meteorites. But this is the first time an amino acid has turned up in comet material.
"This is yet another piece of evidence that the ingredients for life are ubiquitous. These building blocks of life are everywhere," said Carl Pilcher, director of NASA's Astrobiology Institute, which helped fund the research. Pilcher said the discovery strengthens the argument that life in the universe may be common, rather than rare.
Monday, August 24, 2009
Amino acids in comet tail
From the LA Times.