Abstract

“Professor Monica Grady is a leading British space scientist, primarily known for her work on meteorites. She is currently Professor of Planetary and Space Science at the Open University. She was part of the team that developed the Ptolemy instrument on Philae, which seeks to explore the relationship between water ice on comets and the Earth’s oceans and to study the nature of organic material on the comet and thus investigate the relationship with similar materials from other Solar System bodies. The instrument combines gas chromatography and mass spectrometry to measure the isotope ratios of Hydrogen, Carbon, Nitrogen and Oxygen. The ratios of heavy to light isotopes (e.g. 18O/16O in H2O ) act as fingerprints to determine where a sample of water came from.”