Cache Valley-built space surveyer completes work
By Kevin Opsahl
The Herald Journal
March 19, 2012
The Heart and Soul nebulae are seen in this infrared mosaic from NASA's Wide-field Infrared Survey Explorer, or WISE. The image covers an area of the sky over ten times as wide as the full moon, and eight times as high (5.5 x 3.9 degrees), in the constellation Cassiopeia.
NORTH LOGAN — The images of space taken from WISE, the satellite built at Utah State University’s Space Dynamics Laboratory, are now available to stargazers and researchers all over the world.
According to a USU press release detailing NASA’s announcement, the individual WISE exposures have been combined into an atlas of more than 18,000 images covering the sky and a catalog listing the infrared properties of more than 560 million individual objects found in the images. Most of the objects are stars and galaxies, with roughly equal numbers of each. Many of them have never been seen before.
A preliminary release of WISE data, covering the first half of the sky surveyed, was made last April. The final data dump now means WISE has officially completed its mission, officials from the USU Research Foundation stated in a press release.
WISE — short for Wide-field Infrared Survey Explorer — launched Dec. 14, 2009, and mapped the entire sky in 2010 with vastly better sensitivity than its predecessors. It collected more than 2.7 million images taken at four infrared wavelengths of light, capturing everything from nearby asteroids to distant galaxies. Since then, the team has been processing more than 15 trillion bytes of returned data.
SDL’s John Elwell, who was WISE's lead engineer, said he was amazed at the images released Thursday.
“It’s pretty stunning; they’re beautiful; it’s a lifetime’s work to look at all of that data,” Elwell said. “There’s many astrophysicists around the world looking for their favorite objects.”
He continued, “We’ve learned a huge amount. For example, close to home, scientists have already been able to update models for the likelihood of large asteroids hitting Earth, dinosaur killers ... the good news is the chance of a large asteroid hitting us on the head is a lot lower than previously thought.”
Elwell said the study of a new temperature-cool star called a “brown dwarf” will continue. Because those types of stars have been cooling since their formation, they don't shine in visible light and could not be spotted until WISE mapped the sky with its infrared vision.
Scientists were also able to find the first-ever asteroid with the same orbit as Earth. Neptune, Jupiter and Mars also have these so-called Trojan asteroids, but Earth’s had been difficult to find because they’re only visible in daylight.
Niel Holt, director of SDL, said the all-sky survey is the culmination of years of hard work by the men and women of SDL and “our team members at NASA's Jet Propulsion Laboratory, UCLA, UC Berkeley and Ball Aerospace. We are honored that SDL played a significant role in this very important science mission that will provide new data about our universe for decades to come.”
A collection of WISE images can be seen at http://wise.ssl.berkeley.edu/gallery_images.html. The public archive for astronomers is online at http://wise.ssl.berkeley.edu/wise_image_service.html.
© 2012 The Herald Journal