Wide-Field Infrared Survey Explorer
Wide - Field Infrared Survey Explorer (WISE, planned as a Next Generation Sky Survey, NGSS ) is an unmanned space telescope of NASA, which looked through the entire sky in the mid-infrared region from January 2010. After the successful launch it was also named Explorer 92 was taken out of service in February 2011, but reactivated in the fall of 2013, a further three years template: / seek future in 3 years for asteroids.
Tasks
Among the objects WISE examined include
- Asteroids and other solar system objects. WISE will find all the asteroids of the main belt with more than 3 km in diameter
- Cool and faint stars, including the sun nearest stars and brown dwarfs
- If the hypothetical star Nemesis should be a brown dwarf, WISE would have discovered it.
- Young stars in the Milky Way and dust disks around evolved stars already
- The most luminous galaxies and infrared galaxies.
Objectives and capabilities go beyond the failed Wide -Field Infrared Explorer mission. The sky survey of WISE is about one hundred times more sensitive than the surveys of IRAS and Akari at comparable wavelengths, and thus provides an important basis for many future studies.
Construction
WISE was built by Ball Aerospace and had a launch mass of 661 kg. It consumes 301 watts of power, supplied by a solar field with 551 watts maximum power. The telescope WISE has a diameter of 40 cm, the optics and detectors are cooled by a cryostat with solid hydrogen. Was observed in four wavelength bands of 3.3, 4.7, 12 and 24 microns, according to consumption of the refrigerant in the extending issues only the detectors for the three shorter wavelengths in use.
Mission History
Start and first screening
The launch took place on 14 December 2009 at 14:09:33 UTC clock with a Delta II 7320 -10C rocket from Vandenberg Air Force Base. The 525 km high orbit is sun-synchronous, and is always higher than the Twilight line. WISE looks always away from Earth and moves uniformly across the sky, but a movable mirror freezes the field of view of 47 ' × 47' for a few seconds on the detectors with 1024 × 1024 pixels of one. On December 29, 2009, the cap of the telescope was jettisoned. The first pictures of the mission were released after the full calibration of WISE on January 6, 2010. In the second half of July 2010, WISE completed the first all-sky survey, for which he made 1.3 million images within half a year.
Second screening and decommissioning
October 5, 2010 it was announced that after 1.5 sky surveys of hydrogen is evaporated and the telescope has therefore heated to -203 ° C. The mission was continued under the name Neowise to January 2011, as the sensors for the three shorter wavelengths even at the higher temperature still function satisfactorily. The second sky survey has been completed and analyzed asteroids and comets in our solar system. On 17 February 2011 the channel of WISE was shut down and placed the satellite in a quiescent state from which he could be awakened with appropriate funding for further use again.
Reactivation
In August 2013, NASA announced that it would reactivate WISE to detect asteroids for three years. WISE will however be only several months later operational since the first telescope to cool down and then calibrated. This application also will bear the project name Neowise. After WISE end of December 2013 had cooled to less than -200 ° C, started within the mission Neowise further observations. On December 29, the space telescope discovered a previously unknown, low-earth orbit object, the asteroid 2013 YP139.
Results
In evaluating the data, a group of the Jet Propulsion Laboratory and discovered approximately 2.5 million previously unknown, massive and active black holes. Furthermore, enveloped by clouds of dust islands of stars could be tracked, whose brightness higher than our Milky Way. However, they can only be detected indirectly because their visible spectrum is shielded by the dust.
When looking for a large Planet X, it has not determined the planet of Jupiter size within 26,000 AU distance from the Sun.