My research interests are space plasma physics, outer planet magnetospheres, solar wind in the outer heliosphere, and astrophysical plasmas. I was Principal Investigator on the Voyager Plasma Science Experiment during the Voyager Nepture Encounter--the end of the Grand Tour. I am now a Co-Investigator on the Plasma Science Experiment onboard the Voyager Interstellar Mission.

Voyager 2 crossed the solar wind termination shock in August of 2007 (see figure below). Voyager 1 crossed the heliopause into the interstellar medium in August of 2012. The Voyager 2 crossing of the heliopause occurred in November of 2018, and for the first time the MIT instrument on board Voyager 2 measuried the properties of the local interstellar medium in situ.

Because of the decreasing power from the Voyager RTGs, the PLS instrument was turned off in October of 2024.