NASA's WISE Mission Warms Up But Keeps Chugging Along

After completing its primary mission to map the infrared sky, NASA's Wide-field Infrared Survey Explorer, or WISE, has reached the expected end of its onboard supply of frozen coolant. Although WISE has 'warmed up,' NASA has decided the mission will still continue. WISE will now focus on our nearest neighbors the asteroids and comets traveling together with our solar system's planets around the sun. "Two of our four infrared detectors still work even at warmer temperatures, so we can use those bands to continue our hunt for asteroids and comets," said Amy Mainzer of NASA's Jet Propulsion Laboratory in Pasadena, Calif. Mainzer is the principal investigator of the new phase of the mission, now known as the NEOWISE Post-Cryogenic Mission.

It takes its name from the acronym for a near-Earth object, NEO, and WISE. A cryogen is a coolant used to make the detectors more sensitive. In WISE's case, the cryogen was frozen hydrogen. WISE launched Dec. 14, 2009, from Vandenberg Air Force Station in California aboard a Delta II launch vehicle. Its 16-inch infrared telescope scans the skies from an Earth-circling orbit crossing the poles. It has already snapped more than 1.8 million pictures at four infrared wavelengths. Currently, the survey has covered the sky about one-and-one-half times, producing a vast catalog containing hundreds of millions of objects from near-Earth asteroids to cool stars called "brown dwarfs" to distant, luminous galaxies.

To date, WISE has discovered 19 comets and more than 33,500 asteroids, including 120 near-Earth objects, which are those bodies with orbits that pass relatively close to Earth's path around the sun. More discoveries regarding objects outside our solar system, such as the brown dwarfs and luminous galaxies, are expected. "The science data collected by WISE will be used by the scientific community for decades," said Jaya Bajpayee, the WISE program executive in the Astrophysics Division of NASA's Science Mission Directorate at the agency's Headquarters in Washington. "It will also provide a sky map for future observatories like NASA's James Webb Space Telescope."

Fermi Detects 'Shocking' Surprise from Supernova's Little Cousin

Astronomers using NASA's Fermi Gamma-ray Space Telescope have detected gamma-rays from a nova for the first time, a finding that stunned observers and theorists alike. The discovery overturns the notion that novae explosions lack the power to emit such high-energy radiation. A nova is a sudden, short-lived brightening of an otherwise inconspicuous star. The outburst occurs when a white dwarf in a binary system erupts in an enormous thermonuclear explosion. "In human terms, this was an immensely powerful eruption, equivalent to about 1,000 times the energy emitted by the sun every year," said Elizabeth Hays, a Fermi deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "But compared to other cosmic events Fermi sees, it was quite modest. We're amazed that Fermi detected it so strongly."

Gamma rays are the most energetic form of light, and Fermi's Large Area Telescope (LAT) detected the nova for 15 days. Scientists believe the emission arose as a million-mile-per-hour shock wave raced from the site of the explosion. A paper detailing the discovery will appear in the Aug. 13 edition of the journal Science. The story opened in Japan during the predawn hours of March 11, when amateur astronomers Koichi Nishiyama and Fujio Kabashima in Miyaki-cho, Saga Prefecture, imaged a dramatic change in the brightness of a star in the constellation Cygnus. They realized that the star, known as V407 Cyg, was 10 times brighter than in an image they had taken three days earlier.

The team relayed the nova discovery to Hiroyuki Maehara at Kyoto University, who notified astronomers around the world for follow-up observations. Before this notice became widely available, the outburst was independently reported by three other Japanese amateurs: Tadashi Kojima, Tsumagoi-mura Agatsuma-gun, Gunma prefecture; Kazuo Sakaniwa, Higashichikuma-gun, Nagano prefecture; and Akihiko Tago, Tsuyama-shi, Okayama prefecture. On March 13, Goddard's Davide Donato was on-duty as the LAT "flare advocate," a scientist who monitors the daily data downloads for sources of potential interest, when he noticed a significant detection in Cygnus. But linking this source to the nova would take several days, in part because key members of the Fermi team were in Paris for a meeting of the LAT scientific collaboration.

NASA Telescope Peers Into Heart and Soul of world

Two massive, bubbling clouds of star-making factories were captured in a stunning photo by a NASA space telescope that is surveying the whole sky in infrared light. The huge mosaic of the Heart and Soul nebulae was taken by the Wide-field Infrared Survey Explorer space telescope, which has finished approximately three-fourths of its infrared survey of the entire sky. A NASA advisory panel recently suggested that the telescope's mission end in October as planned, instead of extending its imaging work.

WISE was designed to detect the faint glow of distant objects with instruments chilled to the point where they make no detectable infrared light. Currently, WISE is producing approximately 7,500 images a day in each of four infrared wavelengths. "This new image demonstrates the power of WISE to capture vast regions," said Ned Wright, the mission's principal investigator at UCLA, who presented the new picture today at the 216th conference of the American Astronomical Society in Miami. "We're looking north, south, east and west to map the entire sky."