My primary research interests are in the laboratory analysis and scientific implications of extraterrestrial materials, including meteorites and interplanetary dust particles. I am very interested in presolar grains in meteorites and in the development of new techniques for isotopic analysis and mapping of small samples. I am actively involved in the analysis of cometary samples returned by NASA's STARDUST mission and solar wind samples returned by the GENESIS mission.

Click here for more information about presolar grains (very old site).

Planetary Missions

I also work on X-ray and Gamma-ray spectrometers for planetary missions. I was a team member of the Near Earth Asteroid Rendezvous mission to asteroid 433 Eros and served as Deputy PI for NASA's MESSENGER mission, the first spacecraft to visit the planet Mercury since 1975. It flew by the planet 3 times before its a four-year orbital mission from 2011-2015. I am a member of the X-ray spectrometer team for the ESA/JAXA Mercury mission, BepiColombo, to be launched in November 2018.

I am also a NASA Participating Scientist on JAXA's Hayabusa2 asteroid sample return mission. Hayabusa2 arrived at asteroid (162173) Ryugu in summer 2018 and will return a sample to Earth in late 2020.