Satellite produces dramatically sharp 'baby picture' of the universe
Results from NASA/Princeton partnership herald 'a turning point for cosmology'

by Steven Schultz
NASA announced Tuesday, Feb. 11, that a satellite built in partnership with Princeton scientists has captured a high-resolution snapshot of the universe in its infancy and produced dramatic insights into astronomy and physics.

The Wilkinson Microwave Anisotropy Probe, a satellite designed and built in a partnership between Princeton and NASA.  

Answers to longstanding questions about the age, composition and evolution of the universe snapped into sharper focus with the arrival of the data, which came from a yearlong observation of remnants of light from the big bang itself.

"We have a map of the earliest light of the universe that is complete, and it is stunning to look at," said Princeton physicist Lyman Page.

The space agency also announced that it has named the satellite that collected the data in honor of Princeton physicist David Wilkinson, who was a founding member of the project team and who died in September 2002. The Wilkinson Microwave Anisotropy Probe measures slight ripples -- or anisotropies -- in the big-bang afterglow that suffuses the universe.

Among the most surprising results is the discovery that the first stars formed just 200 million years after the big bang, sooner than previously thought. Scientists had thought that the first stars formed when the universe was 800 million years old.

Other implications arising from the data include:

  • A dramatically sharper measure of the age of the universe -- 13.7 billion years, plus or minus .2 billion years. That margin of error is no more than the length of time dinosaurs roamed the earth; previous estimates had uncertainties many times larger.
  • A refined estimate of how much matter exists in the universe and strong evidence that the universe is dominated by some form of "dark energy" that is tearing it apart. According to the project scientists, the universe consists of 4 percent ordinary matter, 23 percent dark matter of unknown form and 73 percent dark energy. Some previous studies had suggested more matter and less dark energy.
  • A revised and more complex picture of the first microseconds of the big bang, when the universe appears to have undergone a period of hyperfast expansion called inflation.

"These numbers represent a milestone in how we view our universe," Anne Kinney, NASA director for astronomy and physics, said in the space agency's news release. "This is a true turning point for cosmology."

"The really remarkable thing is that it all fits," said David Spergel, a Princeton astrophysicist and a participant in the project. The data tie together many previous observations from the Hubble Space Telescope and other sources, essentially completing the basic picture of how the universe began, he said.

The full story is available in a news release.


David Wilkinson, the late Princeton physicist for whom the satellite was named.

The Wilkinson Microwave Anisotropy Probe produced a map of the afterglow of the big bang with far greater resolution than ever before. The top image shows a map that resulted from NASA's COBE satellite, which discovered faint ripples in the radiation in 1992. The bottom image shows the results from the Wilkinson satellite, which has 35 times greater resolution and 45 times greater sensitivity than COBE..

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