Chemists from the University of California, Berkeley, and the University of Hawaii, Manoa, say an experiment simulating conditions in deep space showed such conditions are capable of creating complex dipeptides -- linked pairs of amino acids -- that are essential building blocks shared by all living things.
The discovery suggests the possibility these molecules were "seeded" to Earth by a comet or possibly meteorites, catalyzing the formation of proteins (polypeptides), enzymes and even more complex molecules, such as sugars, that are necessary for life, a UC Berkeley release reported Tuesday.
"It is fascinating to consider that the most basic biochemical building blocks that led to life on Earth may well have had an extraterrestrial origin," UC Berkeley chemist Richard Mathies said.
In an ultra-high vacuum chamber chilled to 10 degrees above absolute zero, University of Hawaii researchers simulated an icy snowball in space including carbon dioxide, ammonia and various hydrocarbons such as methane, ethane and propane.
When bombarded with high-energy electrons to simulate cosmic rays in space, the chemicals reacted to form organic compounds essential to life.
An analysis at Berkeley confirmed the presence of complex molecules -- nine amino acids and at least two dipeptides -- capable of catalyzing biological evolution on Earth.