NASA Releases Stunning Images Of Our Infant Universe
|
Full-sky map of the oldest light in the
universe. The colors indicate "warmer" (red) and "cooler" (blue)
spots, with differences being a few millionths of a degree. The oval shape is a projection to display the whole sky; similar to the way the globe of the earth can be represented as an oval. (Credit: NASA/WMAP Science Team) |
|
NASA today released the best "baby picture" of the
Universe ever taken; the image contains such stunning detail
that 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, acquired the new cosmic portrait by observing
the cosmic microwave background, which is the afterglow
of the big bang.
"We've captured the infant universe in sharp focus, and from
this portrait we can now describe the universe with
unprecedented accuracy," said Dr. Charles L. Bennett of the
Goddard Space Flight Center (GSFC), Greenbelt Md., and the
WMAP Principal Investigator. "The data are solid, a real gold
mine," he said.
The new portrait precisely pegs the age of the
Universe at 13.7 billion years old, with a remarkably small
one percent margin of error. In addition, the WMAP results indicate
that the geometry of the universe is flat, so the Euclidean geometry
you learned in high school applies over very large distances.
|
This animation (5.0 MB) shows how the structure of the universe evolved from WMAP's "baby picture" of the Big Bang. Matter clumps under the force of gravity, then the first stars ignite, and finally the structures of galaxies form. (Credit: NASA/WMAP Science Team /WMAP Science Team) |
|
The WMAP team found that the Big Bang and Inflation theories
continue to ring true. The contents of the universe include
only 4 percent atoms (ordinary matter), 23 percent of a cold dark
matter, and 73 percent of a mysterious dark energy. Scientist
do not know what makes up the cold dark matter, and understand
dark energy as a force acting against gravity which causes the
universe to accelerate its expansion.
One of the biggest surprises revealed in the data is the
first stars in the Universe began to shine only 200 million
years after the big bang, much earlier than many scientists
had expected.
"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."
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 the extraordinarily evenly dispersed
microwave light bathing the universe, which now averages a
frigid 2.73 degrees above absolute zero. WMAP
detects slight temperature fluctuations, which vary by only
millionths of a degree.
|
The pattern WMAP observed is like a
fingerprint. Each theory of the Universe makes a specific prediction
about the make-up of the universe, its shape, and intensity of the microwave 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. (Credit: NASA/WMAP Science Team) |
|
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's results can thus be used to rule out
certain theories within the Inflationary Universe paradigm.
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 the 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 June 30, 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.
Additional Links
Visit the WMAP (http://map.gsfc.nasa.gov/) site!
|