Distant Molecules

Distant Molecules Combining the techniques of the chemistry laboratory with the tools of the observatory, radio astronomers have recently discovered at least 13 different kinds of molecules in the vast spaces between the stars of the earth's galaxy (TIME, June 8, 1970). Now the hunting grounds of astrochemistry, as the new discipline is called, have been enormously expanded. French Astronomer Leonid N. Weliachew, 34, reported last week that he had found the first tantalizing evidence of molecule building in galaxies beyond the Milky Way. His finding was one more indication that life may not be unique to earth.

Resolving Power. Other astronomers have also looked for extragalactic molecules, but without any luck. Lacking sufficiently sensitive radio telescopes, they could not detect the faint "signatures" left by such molecules in the radio waves coming from distant galaxies. To overcome that obstacle, Weliachew, now a visiting astronomer at Caltech, hooked up the school's three big antennas in California's Owens Valley--two 90-ft. dishes and a 130-ft. dish --so that any two of them could be used simultaneously. That technique gave him the resolving power of a huge single antenna with a diameter equal to the distance between the two antennas (up to 3,500 ft.). Then, aiming his twin instruments at two particularly powerful sources of radio energy, the galaxies M82 and NGC 253, * he quickly found what he was looking for: the characteristic signature of hydroxyl radicals, simple molecules composed of a single hydrogen and a single oxygen atom.

Such examples of chemical evolution are an essential first step in the construction of amino acids and proteins, complex molecules that are the building blocks of life itself. Thus, Weliachew has provided significant support for the belief of a growing number of scientists that the same chemical processes that likely produced life on earth are occurring throughout the universe. "I don't smile at the thought of finding intelligent life in the universe," says Weliachew. "It is a serious matter."

* M82 stands for object No. 82 in the catalogue of nebulae, galaxies and clusters of stars started by the 18th century French astronomer Charles Messier. NGC 253 means object No. 253 in the New General Catalogue.

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