An amino acid, one of the building blocks of life, has been spotted in deep space. If the find stands up to scrutiny, it means that the sorts of chemistry needed to create life are not unique to Earth verifying one of astrobiology's cherished theories.
This would add weight to ideas that life exists on other planets, and even that molecules from outer space kick-started life on Earth.
Over 130 molecules have been identified in interstellar space so far, including sugars and ethanol. But amino acids are a particularly important find because they link up to form proteins, the molecules that run, and to a large extent make up our cells.
Back in 1994, a team led by astronomer Lewis Snyder of the University of Illinois at Urbana-Champaign announced preliminary evidence of the simplest type of amino acid, glycine, but the finding did not stand up to closer examination (New Scientist magazine, 11 June 1994, p 4).
Now Snyder and Yi-Jehng Kuan of the National Taiwan Normal University say they really have found glycine. "We're more confident [this time]," says Kuan. "We have strong evidence that glycine exists in interstellar space."
Huge blobs
The researchers monitored radio waves for the spectral lines characteristic of glycine. They studied emissions from more locations than before - giant molecular clouds, huge blobs of gas and dust grains. They have also identified 10 spectral lines at each location that correspond to the lines created by glycine in the lab; before they had just two.
The discovery of glycine supports recent lab-based simulations of deep space, which show that ices containing simple organic matter could form. When researchers bathe those ices in ultraviolet light, amino acids are created.
"Glycine is the holy grail," says Jill Tarter, director of the Centre for SETI Research at the SETI Institute in Mountain View. "Let's hope they've got it this time."
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