11 February 2003
NASA reveals stunning images of infant universe
Greenbelt, Md. – NASA released Tuesday the best "baby picture" of the Universe ever taken – an image containing such detail that NASA claims it may be one of the most important scientific results of recent years.
Scientists using NASA's Wilkinson Microwave Anisotropy Probe (WMAP), during a sweeping 12-month observation of the entire sky, captured the new cosmic portrait, capturing the afterglow of the big bang, called the cosmic microwave background.
First detailed, all-sky picture of the infant universe. The WMAP image reveals 13 billion+ year old temperature fluctuations (shown as color differences) that correspond to the seeds that grew to become the galaxies. NASA says encoded in the patterns are the answers to many age-old questions, such as the age and geometry of the universe.
NASA Goddard Space Flight Center image
"We've captured the infant universe in sharp focus, and from this portrait we can now describe the universe with unprecedented accuracy," said Charles L. Bennett of the Goddard Space Flight Center (GSFC), Greenbelt, Md. and WMAP principal investigator. "The data are solid, a real gold mine," he said.
One of the biggest surprises revealed in the data is the first generation of stars to shine in the universe first ignited only 200 million years after the big bang – much earlier than many scientists had expected.
In addition, the new portrait precisely pegs the age of the universe at 13.7 billion years old, with a remarkably small 1% margin of error.
The WMAP team found the big bang and Inflation theories continue to ring true. The contents of the universe include 4% atoms (ordinary matter), 23% of an unknown type of dark matter, and 73% of a mysterious dark energy. The new measurements even shed light on the nature of the dark energy, which acts as a sort of an anti-gravity.
"These numbers represent a milestone in how we view our universe," said Dr. Anne Kinney, NASA director for astronomy and physics. "This is a true turning point for cosmology."
NASA said the light we see today, as the cosmic microwave background, has traveled over 13 billion years to reach us. Within this light are infinitesimal patterns that mark the seeds of what later grew into clusters of galaxies and the vast structure we see all around us.
Patterns in the big bang afterglow were frozen in place only 380,000 years after the big bang, a number nailed down by this latest observation. These patterns are tiny temperature differences within this extraordinarily evenly dispersed microwave light bathing the universe, which now averages a frigid 2.73 degrees above absolute zero temperature. WMAP resolves slight temperature fluctuations, which vary by only millionths of a degree.
Theories about the evolution of the universe make specific predictions about the extent of these temperature patterns. Like a detective, the WMAP team compared the unique "fingerprint" of patterns imprinted on this ancient light with fingerprints predicted by various cosmic theories and found a match.
WMAP will continue to observe the cosmic microwave background for an additional three years, and its data will reveal new insights into the theory of Inflation and the nature of the dark energy.
"This is a beginning of a new stage in our study of the early universe," said WMAP team member Prof. David N. Spergel of Princeton University, N.J. "We can use this portrait not only to predict the properties of the nearby universe, but can also use it to understand the first moments of the big bang," he said.
WMAP is named in honor of David Wilkinson of Princeton University, a world-renown cosmologist and WMAP team member who died in September 2002.
Launched on 30 June 2001, WMAP maintains a distant orbit about the second Lagrange Point, or "L2," a million miles from Earth.
WMAP is the result of a partnership between the GSFC and Princeton University. Additional Science Team members are located at Brown University, Providence R.I., the University of British Columbia, Vancouver, BC, the University of Chicago, and the University of California, Los Angeles. WMAP is part of the Explorer program, managed by GSFC.
For more information, images and videos see NASA Goddard Space Flight Center's Web site.
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