spacetoday.net: NASA probe data supports Big Bang inflation model

Posted: Wed, Feb 12, 2003, 8:17 AM ET (1317 GMT)
WMAP image of cosmic microwave background (NASA)

New results from a NASA astronomy spacecraft has provided additional evidence supporting the leading model to explain the origin and early history of the universe. The Wilkinson Microwave Anisotropy Probe (WMAP) spacecraft carried out a 12-month observation of the sky in an effort to map the cosmic microwave background, a signature of light from the early universe, at unprecedented resolution. The WMAP results show that the universe is 13.7 billion years old, with a margin of error of only one percent. It also finds that only four percent of the universe is made of ordinary matter, with 23 percent made of dark matter with the remaining 73 percent an unknown dark energy that appears to cause the universe to expand at an accelerating rate. The data also supports a model of the Big Bang called inflation, where the universe greatly expanded in the first instant after the Big Bang. One surprising find from the data was the discovery that the earliest stars formed just 200 million years after the Big Bang, far earlier than previously believed. One prominent cosmologist, John Bahcall, called the results from WMAP "a rite of passage for cosmology from speculation to precision science." WMAP was launched in June 2001 as MAP; the spacecraft was officially renamed Tuesday in memory of the late cosmologist David Wilkinson.