A new portrait of the universe, 14 years in the making by NASA’s workhorse Wide-field Infrared Survey Explorer space telescope, reveals a surprising half-billion celestial objects — some far and others quite close and potentially imposing.
The $320 million mission was de-commissioned on Dec. 17, 2011, after two years of circling the Earth.
But the value of the 2.7 million images the satellite’s four imagers collected with unprecedented sensitivity promise to keep on giving.
This week, the space agency produced an atlas of more than 18,000 images covering the entire sky and spotlighting 560 million objects.
Some of WISE’s most remarkable accomplishments include:
*A poll of near-Earth asteroids, the kinds of difficult to detect planetary objects that sweep close enough to our planet to pose a potential collision threat.
The WISE imagery found fewer NEAs than previously estimated, and confirmed that NASA has identified more than 90 percent of them, a goal Congress set for the agency in 1998.
Using WISE imagery, experts now place the numbers of NEAs at closer to 19,500, rather than 35,000. These objects range from 330 to 3,300 feet across.
*The discovery of an elusive class of “cool” stars. Astronomers have been looking for “Y-dwarf” stars for more than a decade. WISE was uniquely qualified to find this class of solar objects that have been cooling off since they formed.
*The discovery of the Earth’s first known Trojan asteroid. The planetary object follows the Earth as it orbits the sun.
“With the release of the all-sky catalogue and atlas, WISE joins the pantheon of great sky surveys that have led to many remarkable discovereis about the universe,” said Roc Cutri, who lead the data processing and archiving effort based at the California Institute of Technology. “It will be exciting and rewarding to see the innovateive ways th science and eductional communities will use WISE in their studies now that they have the data at their fingertips.”
Planning for WISE began in 1998.