I am chuffed to say that John Mather has won a Nobel Prize!
John was the Principal Investigator (i.e. the Big Cheese) for COBE, the COsmic Background Explorer, a mission that launched in 1989. Equipped with three detectors sensitive to far-infrared, microwaves, and radio waves, COBE was designed to look for the emission "left over" from the Big Bang. Initially the Universe was incredibly hot, but as it expanded it cooled. As a gas cools (and the Universe in those times behaved very much like a gas) it emits radiation at lower and lower wavelengths -- at first the light filling the Universe was super-high-energy gamma rays, but then it cooled down through X-rays, UV, visible light, then infrared. Nowadays the original fireball glows feebly in microwaves. This glow is called the Cosmic Microwave Background, or CMB.
It was predicted to exist decades ago, but the technology wasn't good enough to see it in detail until the 1970s and 80s. People had tried to see it, but it was a very difficult observation to do from the ground. COBE was launched into space where the Earth doesn't interfere nearly as much.
The first results from COBE were announced at the 1990 American Astronomical Society meeting. When a plot showing the CMB radiation was displayed, it got a standing ovation. This was solid evidence supporting the Big Bang model, and so it was huge news. I was at that meeting (it was my first one, actually) and I kick myself to this day that I missed that session. It was a piece of history!
COBE kept plugging away, eventually putting together about 4 years worth of data. By that time I had gotten my PhD, and been hired by a contractor to work on some COBE data. That's a long and somewhat boring story, but even though my contribution to the COBE project was really very minimal, it gives me (totally unearned) pride to know that the Big Boss, John Mather (along with his co-investigator George Smoot) has been recognized for his vision on that project. He now works on the James Webb Space Telescope, a 6-meter infrared telescope due for launch in the next few years.
I don't know John very well, but I do know he is a nice guy, soft-spoken, who wants to more or less avoid the limelight and just figure out what makes the Universe tick. It's scientists like him who push forward our knowledge of Nature. Congratulations, John and George!
And because I simply cannot resist-- take that, creationists! The Universe is so older than 6000 years.
Image courtesy of JWST/NASA