Planck sees sky in new light
BY STEPHEN CLARK
Posted: July 5, 2010
The European Space Agency released a spectacular picture of the microwave sky Monday, an artful mosaic of interstellar dust and the relic light from the birth of the universe.
"This is the moment that Planck was conceived for," said David Southwood, ESA's director of science and robotic exploration.
The picture is dominated by intense microwave radiation from the Milky Way galaxy, visible as a disc of bright blue light across the width of the all-sky map.
Planck's two science-gathering instruments are sensitive to tiny variations in temperature, so the telescope is able to resolve frigid regions of the galaxy full of star-forming dust. The filaments of purple light above and below the Milky Way core are examples of these hidden stellar nurseries.
But Planck's ultimate objective is to map the cosmic microwave background radiation 380,000 years after the Big Bang. The CMB is considered the first light from the young universe after matter and light could exist independently as the universe cooled.
"We're not giving the answer," Southwood said. "We are opening the door to an Eldorado where scientists can seek the nuggets that will lead to deeper understanding of how our universe came to be and how it works now. The image itself and its remarkable quality is a tribute to the engineers who built and have operated Planck. Now the scientific harvest must begin."
The CMB is visible near the top and bottom of Monday's all-sky image, appearing as the blotchy red and orange backdrop far beyond the purple of the Milky Way.
Researchers say the CMB shows the distribution of matter and energy just after the Big Bang, before galaxies and stars began forming. Scientists hope to interpret Planck's data to gather clues on how the violent universe just after the Big Bang evolved into more complex structures like galaxies.
Planck can measure the ancient light up to the limits of fundamental astrophysics, obtaining as much information as can possibly be learned by studying the primordial radiation, according to ESA.
The average temperature of the CMB is 2.7 Kelvin, or -455 degrees Fahrenheit. Planck's two instruments can detect variations of about a millionth of that temperature.
The subsequent scans will refine microwave radiation map.
The spacecraft is positioned at the L2 point, a gravity-neutral location about a million miles from Earth.
Planck covers a frequency range 10 times wider than its predecessor, NASA's WMAP mission launched in 2001.
"This image is just a glimpse of what Planck will ultimately see," says Jan Tauber, ESA's Planck project scientist.