Chemistry and astronomy have been historically separate -- the chemical bond was regarded as too fragile to exist in outer space. In fact, the first extraterrestrial chemically-bonded species were not detected until 1940. The rate of new extraterrestrial chemical discoveries has skyrocketed since 1970, and the total of them now stands at 115, ranging from H2 (the smallest) to HC11N (the largest). Most of these extraterrestrial chemical species are long carbon chains not seen on Earth because of their instability in our oxygen-containing atmosphere: cumulenes (whose molecules contain more than two double bonds joining adjacent carbon atoms), polyacetylenes (with carbon chains alternating single and triple bonds), and cyanopolyphenes (HCnN). Laboratory synthesis of extraterrestrial organics
Although extraterrestrial chemical species are detected by their spectra, correct identification requires synthesizing these compounds and measuring their spectra on Earth. This is the research which Patrick Thaddeus of the Smithsonian Institution Observatory and Center for Astrophysics, Harvard University, reported to the New York Section of the American Chemical Society at New York University on 24 January 1998. Thaddeus' field is expanding so rapidly that his title, "Twenty-six New Ring-Chain Molecules," was already out of date. By the time he gave his talk, 27 of these carbon-chain molecules had been synthesized in the lab, far more, in fact, than had been detected in outer space -- with additional molecules emerging at the rate of one every two weeks or so. The largest molecule synthesized so far in the lab contains 17 carbon atoms, while the largest detected so far in outer space has only 11. Nevertheless, Thaddeus expects all the species synthesized on Earth to be detected extraterrestrially in due time.
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