John C. Mather is a senior astrophysicist in the Observational Cosmology Laboratory at NASA’s Goddard Space Flight Center. He leads NASA science teams in their efforts to answer central questions about the whole universe, including: What happened after the Big Bang? How are stars and galaxies and black holes born, how do they grow and what happens when they get old? And what could make life possible on other planets?

As a graduate student at UC Berkeley in the 1970s, Mather had the opportunity to measure the cosmic microwave background (CMB) radiation, the remnant of the Big Bang. He continued to explore this foundational subject at the NASA Goddard Institute for Space Studies, where he led a proposal to build the Cosmic Background Explorer satellite (COBE) that NASA launched in 1989. COBE measured the spectrum of the CMB, matching exactly what the Big Bang theory had predicted, and discovered the hot and cold spots in the radiation that led to our existence. He was awarded the Nobel Prize in Physics for this work in 2006.

In 1995, Mather was tapped to work on the next great space telescope after Hubble. The James Webb Space Telescope launched in 2021 after decades of painstaking work from a team of more than 10,000 people. Now, he is excited for this new powerful tool to probe the mysteries of the early universe, and expand our understanding of the burgeoning number of exoplanets throughout the galaxy and beyond.