ASMS News & Views

Nov 25, 2014

Mass Spectrometry on Comet 67P/Churyumov-Gerasimenko

On November 12th, 2014, after 10 years and travelling more than 6.4 billion kilometers, the European Space Agency’s Rosetta spacecraft successfully delivered a lander named Philae to the surface of the comet 67P/Churyumov-Gerasimenko. One of nine experimental systems on board the lander is a miniaturized GC/MS system called Ptolemy MODULUS ‘Methods Of Determining and Understanding Light elements from Unequivocal Stable isotope compositions’, that incorporates a specially designed quadrupole ion trap mass spectrometer to measure isotope ratios of H, C, N, and O in their various forms within material sampled from the comet subsurface, surface, and near-surface atmosphere. The instrument was constructed with the involvement of Raymond E. March, Professor Emeritus in the Department of Chemistry at Trent University in Peterborough, Ontario, Canada, and John F.J. Todd, Emeritus Professor of Mass Spectroscopy at the University of Kent in the United Kingdom.

Details of the Ptolemy instrument can be found at

An excellent perspective written by Professors March and Todd on the development of Ptolemy MODULUS, entitled “An Ion Trap too Far? The Rosetta Mission to Characterize a Comet.”, can be found in chapter nine of ‘Quadrupole Ion Trap Mass Spectrometry’, 2nd Edition, 2005 John Wiley & Sons, Inc. Wiley has graciously made this chapter available to everyone. Click here to read "An Ion Trap Too Far?"