John Mather shared the Nobel Prize in Physics in 2006 for his work with the Cosmic Background Explorer, or COBE. Launched in 1989, the satellite was instrumental in developing our understanding of cosmic microwave background radiation.
So, what is that?
"The cosmic background is the sort of light and heat that come to us from all directions, way out there from the distant universe. So not coming from objects, but from whatever is really, way farther beyond that," Mather explains.