2 in U.S. Win Nobel Prize for Research of Universe's Origin

So when the COBE results were presented at an American Astronomical Society meeting in 1993, they triggered gasps and later an ovation from the assembled scientists. The work was considered a great feat of experimental science because the faint temperature variations had to be distinguished from background radiation from the solar system, the galaxy and other celestial objects. In addition, the Earth's motion around the sun and the sun's movement around the Milky Way had to be taken into account.

The discovery involved measuring an energy called "blackbody radiation." In its press release, the Nobel committee said that immediately after the big bang, the universe could be compared to a glowing body emitting radiation in which the wavelengths depended solely on its temperature. That form of blackbody radiation was almost 3,000 degrees Celsius (5,432 degrees Fahrenheit) when it was first released.

Scientists had long believed that the radiation gradually cooled as the universe expanded, but Mather and Smoot were the first to measure the temperature of the background radiation. The result was an extremely frigid 455 degrees below zero Fahrenheit.

Following their work, scientific skepticism about the big-bang theory largely disappeared.

The $1.4 million prize was a boost not only for the two winning scientists, but also for NASA scientists in general. Since President Bush announced plans two years ago to send astronauts back to the moon and eventually to Mars, the agency's science programs have been losing budget battles, leading to concern about their future.

Edward Weiler, director of the Goddard Space Flight Center, welcomed the news by saying it is "important to note that COBE was built entirely 'in-house.' " He added: "The fact that a NASA civil servant has won the biggest science award possible demonstrates that world-class research is happening here at NASA."

Scientists have theorized since the 1960s about the existence and importance of cosmic microwave background, and COBE was built at Goddard to measure faraway microwave and infrared light detectable only from outside Earth's lower atmosphere.

The COBE data were analyzed by a team, led by Smoot, that produced maps of the entire sky showing "hot" and "cold" regions with temperature differences of a hundred-thousandth of a degree.

"At the time captured in our images, the currently observable universe was smaller than the smallest dot on your TV screen," Smoot said yesterday.

Since the prizewinning discovery, other astrophysicists have expanded knowledge about the cosmic background radiation and measured it even more precisely. But Mather said yesterday that the next big discoveries are likely to come from NASA's James Webb Space Telescope mission, which is scheduled to launch in 2013. Mather is the mission's senior project scientist.