John Cromwell Mather is an American astrophysicist, cosmologist and Nobel Prize in Physics laureate for his work on the Cosmic Background Explorer Satellite with George Smoot.
This work helped cement the big-bang theory of the universe. According to the Nobel Prize committee, "the COBE-project can also be regarded as the starting point for cosmology as a precision science."
Mather is a senior astrophysicist at the NASA Goddard Space Flight Center in Maryland and adjunct professor of physics at the University of Maryland College of Computer, Mathematical, and Natural Sciences. In 2007, Mather was listed among Time magazine's 100 Most Influential People in The World. In October, 2012, he was listed again by Time magazine in a special issue on New Space Discoveries as one of 25 most influential people in space.
Mather is one of the 20 American recipients of the Nobel Prize in Physics to sign a letter addressed to President George W.