- Since 1937, over 100 molecules have been identified in deep space, almost all from spectral lines in radio wavelengths. Most are carbon-containing molecules ranging in complexity from carbon monoxide (CO) up to such species as methlylacetylene, CH3C2H. The presence of these molecules is a strong indicator of active organic chemistry in space. Inorganic molecules detected include water, sulphur dioxide, common salt (sodium chloride NaCl) and ammonia, NH3. The list grows longer each year and the National Radio Astronomy Observatory in the US is the champion interstellar molecule finder.