In a momentous discovery, the scientists at the Goddard Space Flight Center in Greenbelt, Md., have found 'glycine' - the simplest amino acid and one of life's precursors - in a dust sample from the comet Wild 2.

NASA scientists stated that the discovery substantiates the theory that some essential components of life originated in space and reached the Earth by a comet or meteorite. While amino acids have earlier been discovered in meteorites, it is for the first time that an amino acid has been found in a comet.

The recent discovery, which has been summarized in the journal Meteoritics and Planetary Science, says that the sample was captured by NASA's Stardust spacecraft, which had dropped it into the Utah desert in 2006.

Launched in 1999, the Stardust spacecraft, on a 2.9-billion-mile voyage, five years later met up with the hamburger-shaped comet Wild 2, which orbits between Mars and Jupiter. At its closest approach with the comet, Stardust passed through its tail of dust and gas, and positioned a tennis-racket-shaped collector containing aerogel, a substance that collected comet particles.

According to Jason Dworkin, a coauthor of the research paper, scientists had detected the presence of 'glycine' in the sample from comet a few months after the sample was landed by Stardust. However, the results have been now revealed after their verification for two years.