BUILDING BLOCKS FOR LIFE CAN FORM IN SPACE
How life came into existence is one of science’s greatest mysteries, but a new experiment at the American Institute of Physics suggests that a handful of basic elements and some radiation might be all you need.
A paper in the Journal Of Chemical Physics describes how researchers working in cryogenic conditions coated ice with molecules of carbon dioxide, methane and ammonia, and then exposed the ice to a stream of low-energy electrons, or LEEs. This mimics conditions in space, where such basic molecules can be detected in the ice found on bodies such as comets or moons, where they are subject to bombardment by various forms of radiation including gamma rays, X-rays, LEEs and solar wind particles.
Following the LEE onslaught, the researchers used a spectrometry technique called ‘temperature programmed deportion’ to determine the effects of the radiation, and found that the simple molecules had combined to form glycine, which is an amino acid comprised of hydrogen, carbon, nitrogen and oxygen.
The research suggests that rather than forming here on Earth, amino acids – the building blocks of life – may have formed in space over long periods of time, and then been delivered to our planet by a comet or meteorite impact.
The same team had previously shown that simple molecules in similar conditions could combine to form ethanol, the intoxicating substance found in alcoholic drinks, but glycine is far more complex.
“You just need the right combination of ingredients,” said Michael A Huels, author of the paper. “These molecules can combine, they can chemically react, under the right conditions, to form larger molecules which then give rise to the bigger biomolecules we see in cells like components of proteins, RNA or DNA.”
“AMINO ACIDS MAY HAVE FORMED IN SPACE OVER LONG PERIODS OF TIME, AND THEN BEEN DELIVERED TO OUR PLANET BY A COMET OR METEORITE”