PARIS, Dec 19: A controversial theory that an asteroid or comet seeded life on Earth has been given a boost by a study which has found sugar-related molecules were found in carbon-rich asteroid fragments discovered last century in Australia and the United States, say a team led by George Cooper of NASA’s Ames Research Center.

“We conclude from this that polyols were present on the early Earth and therefore at least available for incorporation into the first forms of life,” they say.

First sketched 40 years ago, the theory of panspermia suggests that a wandering space rock crunched down on the infant Earth around four billion years ago, bearing bacteria that evolved into primitive life forms or maybe the chemical ingredients to kickstart life.

Loathed by the religious right, the idea gained ground among space scientists after meteorites were found to contain amino acids, the basics of proteins.

In addition, experiments showed that these acids could be chemically produced in the laboratory by combining methane and ammonia.

But the missing piece in the puzzle remained polyols, a family of carbon compounds that comprise sugar, sugar alcohols and sugar acids. Polyols provide the “skeleton” for many other molecules as well as a vital energy source for cells.

The scientists used a technique called gas chromatography-mass spectrometry (GC-MS) to heat the samples, turning them into a stream of ionized particles that are then bombarded by electrons to reveal a substance’s molecular weight and hence identity.—AFP