[Thread Ufficiale] NASA Wide-field Infrared Survey Explorer (WISE)

[Xile]

Wide-Field Infrared Survey Explorer (WISE) is a NASA-funded infrared-wavelength astronomical space telescope launched on 14 December 2009. The Earth-orbiting satellite carries a 40-centimetre (16 in) diameter infrared-sensitive telescope, which will survey the entire sky over the course of six months through images made in the 3 to 25 μm wavelength range. The telescope's image detectors are designed to make the survey at least 1,000 times more sensitive to infrared sky features than the sky surveys of previous major infrared space survey telescopes such as the Infrared Astronomical Satellite (IRAS), AKARI and COBE.

The complete mission will create images of 99% of the sky, with at least eight images made of each position on the sky in order to increase accuracy. The spacecraft will be placed in a 525 km (326 mi), circular, polar, sun-synchronous orbit for its 10 month mission, during which it will take 1.5 million images, one every 11 seconds. Each image will cover a 47 arcminute field of view. Each area of the sky will be scanned 10 times. The image library produced will contain data on the local Solar System, the Milky Way Galaxy, and the more distant universe. Among the objects WISE will study are asteroids, cool, dim stars such as brown dwarfs, and the most luminous infrared galaxies.

Construction of the WISE telescope was divided between Ball Aerospace & Technologies Corp. (spacecraft, operations support), SSG Precision Optronics, Inc. (telescope, optics, scan mirror), DRS and Rockwell (focal planes), Lockheed Martin (cryostat, cooling for the telescope), and Space Dynamics Laboratory (instruments, electronics, and testing). The program is managed through the Jet Propulsion Laboratory.

WISE will also serve as a replacement for the Wide Field Infrared Explorer (WIRE) spacecraft, which failed within hours of reaching orbit in March 1999.

The WISE spacecraft was built by Ball Aerospace and Technologies Corp. in Boulder, Colorado. The spacecraft is derived from the Ball Aerospace RS-300 spacecraft architecture, particularly the NEXTSat spacecraft built for the successful Orbital Express mission launched on March 9, 2007. The flight system has an estimated mass of 560 kg (about 1,175 pounds). The spacecraft is three-axis stabilized, with body-fixed solar arrays. It uses a high-gain antenna in the Ku band to transmit to the ground through the TDRSS geostationary system. Ball also performed the testing and flight system integration.

WISE will survey the sky in four wavelengths of the infrared band, at a very high sensitivity. Its detector arrays have 5-sigma sensitivity limits of 120, 160, 650, and 2600 micro-Jansky (µJy) at 3.3, 4.7, 12, and 23 microns.[4] This is a factor of 1,000 times better sensitivity than the survey completed in 1983 by the IRAS satellite in the 12 and 23 micron bands, and a factor of 500,000 times better than the 1990s survey by the Cosmic Background Explorer (COBE) satellite at 3.3 and 4.7 microns.

* Band 1 – 3.4 microns—broad-band sensitivity to stars and galaxies
* Band 2 – 4.6 microns—detect thermal radiation from the internal heat sources of sub-stellar objects like brown dwarfs
* Band 3 – 12 microns—detect thermal radiation from asteroids
* Band 4 – 22 microns—sensitivity to dust in star-forming regions (material with temperatures of 70–100 Kelvin)

A scaffolding structure built around WISE allowed engineers to freeze its hydrogen coolant

The primary mission lasts ten months: one month for checkout, six months for a full-sky survey, then an additional three months of survey until cryogenic coolant runs out. The partial second survey pass will facilitate the study of changes (e.g. orbital movement) in observed objects.

On November 8, 2007, the House Committee on Science and Technology's Subcommittee on Space and Aeronautics held a hearing to examine the status of NASA's Near-Earth Object (NEO) survey program. The prospect of using WISE was proposed by NASA officials.

NASA officials told Committee staff that NASA plans to use WISE to detect near-Earth objects in addition to performing its science goals. It is projected that WISE could detect 400 NEOs (or roughly 2 percent of the estimated NEO population of interest) within its one-year mission.

WISE will not be able to detect Kuiper belt objects, as their temperature is too low. It will be able to detect any objects with an internal heat source: a Neptune-sized object would be detectable out to 700 AU, a Jupiter-mass object out to one light year (63,000 AU), where it would still be within the Sun's zone of gravitational control. A small brown dwarf of 2–3 Jupiter masses would be visible at a distance of up to two to three parsecs.

Wide-field Infrared Survey Explorer

[Rand]

Sono state da poco pubblicate le prime immagini:

(se è troppo grossa e rovina l'impaginazione ditelo che la rimuovo)

NASA's WISE Mission Releases Medley of First Images

PASADENA, Calif. -- A diverse cast of cosmic characters is showcased in the first survey images NASA released Wednesday from its Wide-field Infrared Survey Explorer, or WISE.

Since WISE began its scan of the entire sky in infrared light on Jan. 14, the space telescope has beamed back more than a quarter of a million raw, infrared images. Four new, processed pictures illustrate a sampling of the mission's targets -- a wispy comet, a bursting star-forming cloud, the grand Andromeda galaxy and a faraway cluster of hundreds of galaxies. The images are online at http://www.jpl.nasa.gov/news/features.cfm?feature=2485.

"WISE has worked superbly," said Ed Weiler, associate administrator of the Science Mission Directorate at NASA Headquarters in Washington. "These first images are proving the spacecraft's secondary mission of helping to track asteroids, comets and other stellar objects will be just as critically important as its primary mission of surveying the entire sky in infrared."

One image shows the beauty of a comet called Siding Spring. As the comet parades toward the sun, it sheds dust that glows in infrared light visible to WISE. The comet's tail, which stretches about 10 million miles, looks like a streak of red paint. A bright star appears below it in blue.

"We've got a candy store of images coming down from space," said Edward (Ned) Wright of UCLA, the principal investigator for WISE. "Everyone has their favorite flavors, and we've got them all."

During its survey, the mission is expected to find perhaps dozens of comets, including some that ride along in orbits that take them somewhat close to Earth's path around the sun. WISE will help unravel clues locked inside comets about how our solar system came to be.

Another image shows a bright and choppy star-forming region called NGC 3603, lying 20,000 light-years away in the Carina spiral arm of our Milky Way galaxy. This star-forming factory is churning out batches of new stars, some of which are monstrously massive and hotter than the sun. The hot stars warm the surrounding dust clouds, causing them to glow at infrared wavelengths.

WISE will see hundreds of similar star-making regions in our galaxy, helping astronomers piece together a picture of how stars are born. The observations also provide an important link to understanding violent episodes of star formation in distant galaxies. Because NGC 3603 is much closer, astronomers use it as a lab to probe the same type of action that is taking place billions of light-years away.

Traveling farther out from our Milky Way, the third new image shows our nearest large neighbor, the Andromeda spiral galaxy. Andromeda is a bit bigger than our Milky Way and about 2.5 million light-years away. The new picture highlights WISE's wide field of view -- it covers an area larger than 100 full moons and even shows other smaller galaxies near Andromeda, all belonging to our "local group" of more than about 50 galaxies. WISE will capture the entire local group.

The fourth WISE picture is even farther out, in a region of hundreds of galaxies all bound together into one family. Called the Fornax cluster, these galaxies are 60 million light-years from Earth. The mission's infrared views reveal both stagnant and active galaxies, providing a census of data on an entire galactic community.

"All these pictures tell a story about our dusty origins and destiny," said Peter Eisenhardt, the WISE project scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "WISE sees dusty comets and rocky asteroids tracing the formation and evolution of our solar system. We can map thousands of forming and dying solar systems across our entire galaxy. We can see patterns of star formation across other galaxies, and waves of star-bursting galaxies in clusters millions of light years away."

Other mission targets include comets, asteroids and cool stars called brown dwarfs. WISE discovered its first near-Earth asteroid on Jan. 12, and first comet on Jan. 22. The mission will scan the sky one-and-a-half times by October. At that point, the frozen coolant needed to chill its instruments will be depleted.

JPL manages WISE for NASA's Science Mission Directorate. The mission was competitively selected under NASA's Explorers Program, which NASA's Goddard Space Flight Center in Greenbelt, Md., manages. The Space Dynamics Laboratory in Logan, Utah, built the science instrument, and Ball Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft. Science operations and data processing take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA. For more information about WISE, visit http://www.nasa.gov/wise and http://wise.astro.ucla.edu and http://www.jpl.nasa.gov/wise.

Come missione è decisamente interessante: un'indagine del cielo per catalogare gli oggetti che verranno poi osservati in dettaglio dai telescopi di nuova generazione, sia lontani che vicini (si parla dell'individuazione di circa 100000 nuovi asteroidi).

[lowenz]

Ottimo!

[Xile]

Immagini della nostra vicina Andromeda:







ET sei lì lo so

[jumpjack]

Originariamente inviato da Rand

Sono state da poco pubblicate le prime immagini:.

bah, non mi piacciono, voglio vedere i pianeti. L'hanno lanciato apposta, no^

[frankytop]

Originariamente inviato da Xile

Immagini della nostra vicina Andromeda:







ET sei lì lo so

WOW!