Spunky Satellite Yields Nobel Prize for NASA Scientist
In the early 1970s a young NASA scientist had a crazy idea to build a strange-looking microwave satellite to test the Big Bang theory. After much stress and many false starts, his satellite finally launched in 1989 and by 1990 found nearly irrefutable evidence to support the big bang theory.
Image right: Photo of Dr. John Mather Credit: NASA
On October 3 the Nobel Prize Committee announced that that scientist, John Mather of NASA Goddard Space Flight Center in Greenbelt, Md., will receive the 2006 Nobel Prize for Physics. He shares the prize with long-time colleague George Smoot of the Lawrence Berkeley National Laboratory in Berkeley, Calif.
Until fairly recently very little was known about the origin of the universe. One theory, called the big bang, stated in the simplest of terms that, long ago, something happened and about a billion years later stars and galaxies appeared. John Mather helped fill in the pieces. The satellite mission he led was COBE, the Cosmic Background Explorer.
As early as 1974, Mather was determined to build a satellite that could find evidence for the big bang and how stars and galaxies formed. The big bang theory grew out of Einstein's theory of general relativity and was developed by a Jesuit priest named Georges Lemaitre and others in the 1920s.
The first striking evidence for the big bang came in 1963-1965 when Arno Penzias and Robert Wilson of Bell Laboratories stumbled upon some annoying microwave static interfering with their radio experiment. That interference, responsible for a sizable amount of static seen on your television set, turned out to be remnant radiation from the birth of the universe 13.8 billion years ago. Penzias and Wilson won the Nobel Prize in 1978 for this discovery.
Image left: Mather shows some of the earliest data from the Cosmic Background Explorer satellite during the news conference given at NASA Headquarters on Tuesday, Oct. 3, 2006. Credit: Bill Ingalls, NASA
Mather and Smoot greatly advanced the field by precisely measuring the temperature and spectrum of this cosmic microwave background, the afterglow of the big bang that has cooled considerably but still lingers with us today. If our eyes could detect microwaves, we'd see the entire sky bathed in this light.
The temperature they measured was 2.375 +/- 0.06 Kelvin, or about a minus 455 degrees Fahrenheit. More important, Mather and Smoot found slight temperature fluctuations within this near uniform light, which Stephen Hawking, independent of the COBE team, called "the most important discovery of the century, if not of all time."
Why the hyperbole? The temperature variations (about 10 parts per million) make life possible. Without them, no stars or galaxies or planets would have formed. These variations---a little more heat here, a little less there---pointed to density differences, regions with a little more matter and a little less matter. Through gravity over the course of billions of years, in a cosmic take on the rich get richer, those denser and warmer pockets attracted more matter and heat, which ultimately gave rise to the stars, galaxies and hierarchal structure we see today.
The simplest model of the big bang cannot explain why stars formed; but the tweaked model that Mather and Smoot found evidence for, can explain it.
When Mather presented a chart of the first nine minutes of COBE data at the 1990 meeting of the American Astronomical Society in Washington, he received a standing ovation. Scientists saw instantly how well the COBE data matched the temperature map predicted by theory. Rarely in science is a match between observation and theory so precise. The moment still gives Mather goose bumps today, he said.
Image right: Dr. Mather (kneeling) examines the map of the universe along with Nancy Boggess, Michael Hauser (sitting), and Dr. Chuck Bennett (standing). Click image to enlarge. Credit: NASA
Unlike the Hubble Space Telescope, COBE didn't make optical images of stars and planets, which readily capture the public's imagination. As such, COBE never became a household name, yet its legacy is the Nobel Prize, the first to be award to a NASA scientist. COBE was a homegrown NASA Goddard mission.
The COBE mission ended in 1994 and carried three instruments: The Far Infrared Absolute Spectrophotometer (FIRAS) measured the temperature and spectrum of the cosmic microwave background. Mather, the COBE mission project scientist, was the FIRAS Principal Investigator, and Richard Shafer of NASA Goddard was Deputy P.I. The Differential Microwave Radiometer (DMR) measured the temperature variations, called anisotropy. George Smoot was the DMR Principal Investigator, and Charles L. Bennett, then at Goddard and now at Johns Hopkins University, was the Deputy P.I.
The Diffuse Infrared Background Experiment (DIRBE) measured the cosmic infrared background, the "core sample" of the universe, containing the cumulative emissions of stars and galaxies dating back to the epoch of first light hundreds of millions of years after the Big Bang. The result was surprising: The universe has produced twice as much light as had been thought, and hidden it from view. A previously unknown population of galaxies made this light. Michael Hauser, then at Goddard and now at Space Telescope Science Institute in Baltimore, was the DIRBE Principal Investigator. Tom Kelsall of Goddard was the Deputy.
NASA's Wilkinson Microwave Anisotropy Probe (WMAP), now in orbit, builds on the COBE legacy, exploring in far greater detail the temperature variations the COBE discovered---quite possibly the stuff of future Nobel Prizes.
In August 2006, Mather and the COBE team won the 2006 Gruber Cosmology Prize, also for the big bang discoveries. Along with the scientists mentioned above, the recipients of this award include the members of the COBE Science Working Group: Eli Dwek, S. Harvey Moseley, Robert F. Silverberg, and Nancy Boggess (retired) of NASA Goddard; Edward Cheng, formerly with Goddard and now president of Conceptual Analytics; Samuel Gulkis and Michael A. Janssen of the NASA Jet Propulsion Laboratory; Rainer Weiss of the Massachusetts Institute of Technology; Stephan Meyer of the University of Chicago; Philip Lubin of the University of California, Santa Barbara; Edward Wright of the University of California, Los Angeles; Thomas Murdock of Frontier Technology; and the estate of the late David T. Wilkinson of Princeton University.
+ Feature story on Dr. Mather's Nobel Prize
+ Press Conference photo gallery+ Background on the Cosmic Background Explorer and the Big Bang theory
Goddard Space Flight Center