[citation needed] He was awarded the PhD in Astronomy in 1983 from Harvard University, with a thesis titled "Surveys of Globular Cluster and Galactic Plane X-Ray Sources".

He continued there as an astrophysicist, where his research concentrated on X-ray emission from Galactic neutron stars, black holes, and globular clusters.

[14][15] Around the same time, he announced the cancellation of the Gravity and Extreme Magnetism Small Explorer, saying the technology needed for the instrument was taking longer to develop than expected, driving up the price.

[16][17] He also made the commitment for NASA to provide infrared detectors and science support to the ESA-led Euclid mission.

[11] He is also a published sabremetrician, having proven that there have been a statistically expected number of games played where all seven ways of reaching first base occurred.