Scientists find a building block for life in a comet's halo
Researchers have discovered glycine molecules in samples of cometary material the Stardust spacecraft returned to Earth after its encounter with comet 81P/Wild 2 in 2004.
Glycine is a simple amino acid. It provides the foundation around which other biologically important molecules are built -- including proteins and key components of DNA and RNA.
The discovery "supports the theory that some of life's ingredients formed in space and were delivered to Earth long ago by meteors and comets," notes Jamie Elsila, a researcher with NASA's Goddard Space Flight Institute in Greenbelt, Md.
He and his colleagues reported the results at this week's meeting of the American Chemical Society and a formal report on the work has been accepted for publication in the journal Meteoritics and Planetary Science. You can also find a plain-English version here.
Comets are lumps of ice, rock, and dust several kilometers across that are thought to represent some of the most primitive building blocks for what would become planets and moons. They grow out of the same large cloud of interstellar dust, ice, and gas that spawned the stars they orbit.