Wide-field Infrared Survey Explorer

Wide-field Infrared Survey Explorer is a NASA infrared-wavelength astronomical space telescope launched in December 2009. It was designed to perform an all-sky survey with far greater sensitivity and resolution than its predecessors, such as the Infrared Astronomical Satellite. The mission's primary goal was to map the entire sky in four infrared bands, leading to the discovery of numerous cool stars, brown dwarfs, and previously hidden galaxies.

Overview

The mission was proposed to NASA under its Explorers Program and was developed and operated by the Jet Propulsion Laboratory. The principal investigator was Edward L. Wright of the University of California, Los Angeles. WISE entered a Sun-synchronous orbit around Earth, allowing its telescope to remain cold and avoid heat from the Sun and Earth. Its survey began in January 2010 and scanned the entire celestial sphere one-and-a-half times by February 2011, imaging over a billion objects including asteroids, star-forming regions, and distant starburst galaxies.

Mission and spacecraft

The spacecraft was built by the Space Dynamics Laboratory and launched from Vandenberg Space Force Base atop a Delta II rocket. The telescope used a 40 cm Ritchey–Chrétien design and was cooled by a two-stage hydrogen cryostat. Its focal plane contained four infrared detector arrays, each sensitive to a specific wavelength band crucial for detecting thermal emission from cool objects. After its primary cryogen was exhausted, the mission was reactivated in 2013 as NEOWISE to focus on near-Earth object detection under the Planetary Science Division of NASA.

Scientific objectives and discoveries

A primary objective was to identify the coolest brown dwarfs, sometimes called Y dwarfs, which are extremely difficult to detect at visible wavelengths. WISE discovered hundreds of these objects, including the binary system WISE 1049-5319, one of the closest known stellar systems to the Solar System. It also provided critical data for the Two Micron All-Sky Survey and catalogs like the AllWISE source catalog. The mission identified the first known Earth trojan asteroid, 2010 TK7, and contributed to studies of the structure of our galaxy.

Data releases and legacy

The first major data release occurred in April 2011, with the all-sky data released to the public through the Infrared Science Archive at the Infrared Processing and Analysis Center. Subsequent releases included the AllWISE and unWISE catalogs, which have been used in conjunction with data from the Spitzer Space Telescope and the Hubble Space Telescope. The ongoing NEOWISE mission continues to provide data for planetary defense and has discovered thousands of new minor planets. WISE data also underpinned the Backyard Worlds: Planet 9 citizen science project.

See also

* Astronomical survey * Cosmic Background Explorer * Herschel Space Observatory * James Webb Space Telescope * List of brown dwarfs * Near-Earth Object Wide-field Infrared Survey Explorer * Wide-field Infrared Survey Explorer