U.S. scientists John C. Mather and George F. Smoot won the 2006 Nobel Physics Prize on Tuesday for their work on the Big Bang theory on the origin of the universe.

The Royal Swedish Academy of Sciences said the two men were instrumental to the success of the cosmic background explorer ( COBE) satellite program launched by NASA in 1989.

"The COBE results provided increased support for the Big Bang scenario for the origin of the Universe, as this is the only scenario that predicts the kind of cosmic microwave background radiation measured by COBE," the Academy added.

Under the Big Bang theory, the cosmos was formed from a cataclysmic explosion that happened about 13.7 billion years ago.

Measurements taken by the satellite offered insights into the age of the universe, galaxies and stars by calculating the temperature of cosmic microwave background radiation, a relic of the infant universe, the Nobel jury said.

"These measurements also marked the inception of cosmology as a precise science," it added.

Mather, 60, works at the NASA Goddard Space Flight Center in Greenbelt, Maryland., and Smoot, 61, works at the Lawrence Berkeley National Laboratory in Berkeley, California.

This year's award announcements began Monday with the Nobel Prize in medicine going to Americans Andrew Fire and Craig Mello for their discovery of how to silence malfunctioning genes, offering new hope for fighting diseases as diverse as cancer and AIDS.

The Chemistry Prize will be announced on Wednesday. The Economics Prize is scheduled for Monday, Oct. 9. The Peace Prize -- the only one not awarded in Sweden -- will be announced Oct. 13 in Oslo, Norway.

The date for the Literature Prize has yet to be announced but it is traditionally on a Thursday, and could fall on Oct. 5 or Oct. 12.

The Nobel prizes, founded by Swedish industrialist Alfred Nobel, the inventor of dynamite, were first awarded in 1901.

The 2006 laureates will each receive a gold medal and a diploma and will share a cheque for 10 million Swedish kronor (1.37 million dollars) at the formal prize ceremony slated for Dec. 10, the anniversary of the death in 1896 of the prize's creator Alfred Nobel.

Source: Xinhua