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
|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.
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