The discovery of C60 molecules in 1985 is one of the best known events in the history of nanotechnology, and was recognized with the Nobel Prize in Chemistry in 1996. Less well known is the fact that the motivation for this work came from astrophysics. Indeed, the first sentence of the paper reporting evidence for C60 reads as follows: “During experiments aimed at understanding the mechanisms by which long-chain carbon molecules are formed in interstellar space and circumstellar shells, graphite has been vaporized by laser irradiation, producing a remarkably stable cluster consisting of 60 carbon atoms.” Now, 25 years later, the story has turned full circle with astronomers finding evidence for C60, and also C70, in space for the first time.
Jan Cami of the University of Western Ontario and co-workers in Canada, the United States and France used the Spitzer Space Telescope to study infrared emission from a young planetary nebula called Tc 1. Their results show that the C60 and C70 molecules are cold and neutral, and suggest that they are attached to solid grains of carbonaceous material rather than being free molecules in the gas phase. In laboratory experiments the formation of C60 and C70 is inhibited by the presence of hydrogen, so it seems that Tc 1, unlike most planetary nebulae, contains very little hydrogen.