Tyson was a lecturer in astronomy at the University of Maryland from 1986 to 1987 and in 1988, he was accepted into the astronomy graduate program at Columbia University, where he earned a Master of Philosophy degree in astrophysics in 1989, and a PhD degree in astrophysics in 1991 under the supervision of Professor R. Michael Rich. Rich obtained funding to support Tyson's doctoral research from NASA and the ARCS Foundation, enabling Tyson to attend international meetings in Italy, Switzerland, Chile, and South Africa and to hire students to help him with data reduction. In the course of his thesis work, he observed using the 0.91 m telescope at the Cerro Tololo Inter-American Observatory in Chile, where he obtained images for the Calán/Tololo Supernova Survey helping to further their work in establishing Type Ia supernovae as standard candles.