US space scientists John Mather and George Smoot were awarded the Nobel Physics Prize on Tuesday for a pioneering mission which backed the "Big Bang" theory about the origins of the universe.
The pair were the key minds behind a NASA mission to measure the aftershock of the cataclysmic explosion that occurred some 13.7 billion years ago and gave birth to the cosmos.
The unmanned spacecraft, COBE, not only gave flesh to the skeletal notion of the "Big Bang," which had developed in academic circles in the late 1940s, but also offered clues as to how and when the first galaxies came into being.
The results from COBE were "the greatest discovery of the century, if not all times," the British physicist Stephen Hawking has said.
"These measurements ... marked the inception of cosmology as a precise science," the Nobel jury said in its citation.
Mather, 60, is a senior astrophysicist at NASA's Goddard Space Flight Center in Maryland, while Smoot, 61, is a professor of physics at the University of California at Berkeley.
Mather was lauded for his work on so-called blackbody radiation -- a telltale pattern in the energy spectrum which comes from a body that is cooling down.
At its birth, the universe was 3,000 degrees Celsius. Since then, according to the Big Bang theory, the radiation has gradually cooled as the universe has expanded.
This so-called cosmic microwave background radiation today corresponds to a temperature that is barely 2.7 degrees above absolute zero.
COBE was launched in November 1989.
The first results were received after nine minutes of observations, providing "a perfect blackbody spectrum," in other words -- as predicted -- a temperature profile of the universe at that point after the Big Bang, the Nobel panel said.
When the curve was later shown at an astronomy conference, the results received a standing ovation.
Smoot's prize was for measuring tiny variations in the temperature of this radiation, thus proving the direction of the force of the Big Bang and the still-continuing expansion of the universe.
These temperature differences also amount to fingerprints for cosmic sleuths, as they are the thresholds at which the matter in the infant universe comes together.
Without this aggregation, nothing in today's universe -- the galaxies, stars, life itself -- would exist.
Yesterday's award was a de-facto award for a space mission, the first time this has happened in the history of the Nobel Prize. More than a thousand researchers and engineers worked on the COBE project, which Mather also coordinated.
Last year, the Physic Prize went to Americans Roy Glauber and John Hall and German Theodor Haensch for groundbreaking work on understanding light and optics.
This year's laureates will each receive a gold medal and a diploma and will share a cheque for 10 million kronor (US$1.37 million) at the formal prize ceremony held, as tradition dictates, on Dec. 10, the anniversary of the death in 1896 of the prize's creator Alfred Nobel.