lundi 16 décembre 2019

Celebrating 10 Years of the WISE Spacecraft











NASA - WISE Mission patch / NASA - NEOWISE Mission logo.

December 16, 2019

Image credits: NASA/JPL-Caltech/UCLA

Just before sunrise on Dec. 14, 2009, a Delta-II rocket lifted off from California's Vandenberg Air Force Base and brought NASA's Wide-field Infrared Survey Explorer (WISE) to low-Earth orbit. Its mission: to study galaxies, stars, asteroids and comets by imaging the entire sky in infrared light.

WISE was placed in hibernation in February 2011 after completing its primary astrophysics mission, but in late 2013, the spacecraft was reactivated, renamed NEOWISE and assigned a second mission dedicated to identifying and characterizing the population of near-Earth objects while also providing information about the size and composition of more distant asteroids and comets.

Wide-field Infrared Survey Explorer (WISE) spacecraft. Image Credits: NASA/JPL-Caltech

Over the last decade, data from WISE and NEOWISE have been cited in more than 3,000 peer-reviewed publications and been used to study distant galaxies, cool stars, exploding white dwarfs, outgassing comets, near-Earth asteroids and everything in between.

To celebrate the 10th anniversary of the spacecraft's launch, the mission team has gathered their top 10 images and graphics based on WISE and NEOWISE data.

The Sky as Seen by WISE

Image credits: NASA/JPL-Caltech/UCLA

The fundamental objective of the WISE mission was to map the entire sky in infrared light with hundreds to hundreds of thousands of times greater sensitivity than previous surveys. WISE completed this objective in 2010. This image shows the entire sky as seen by WISE with its four infrared detectors (3.4- and 4.6-micron light is colored blue; 12-micron light is green; and 22-micron light is red), with the plane of our Milky Way galaxy running across the center.

Read more about this image here: https://www.nasa.gov/mission_pages/WISE/multimedia/pia15481.html

Earth's Trojan Asteroid

Image credits: Paul Wiegert, University of Western Ontario - based on WISE/NEOWISE data

Trojan asteroids share an orbit with a planet, orbiting the Sun ahead of or behind the planet. While Trojan asteroids associated with Jupiter, Neptune and Mars are known, NEOWISE discovered the first (and so far only) Trojan asteroid in Earth's orbit, known as 2010 TK7. In this artist's conception, the asteroid is shown in gray and its orbit, which oscillates above and below Earth's every four centuries, is shown in green. Earth's orbit around the Sun is indicated by blue dots.

Read more about this image here: https://www.nasa.gov/mission_pages/WISE/multimedia/gallery/13115-4x3.html

Heart and Soul

Image credits: NASA/JPL-Caltech/UCLA

Located about 6,000 light-years from Earth, the Heart (right) and Soul (left) nebulas compose a vast star-forming complex that makes up part of the Perseus spiral arm of our Milky Way. The Perseus arm lies farther from the center of the Milky Way than the Sun. The nebulas are marked by giant bubbles that were blown into surrounding dust by radiation and winds from stars less than a few million years old - youngsters in comparison to the Sun, which is nearly 5 billion years old.

Read more about this image here: https://www.nasa.gov/mission_pages/WISE/multimedia/wiseimage20100524.html

The Great Galaxy in Andromeda

Image credits: NASA/JPL-Caltech/UCLA

At 2.5 million light-years away, the Andromeda galaxy is the closest spiral galaxy to our Milky Way; in fact, it will collide with ours billions of years from now. This WISE mosaic covers an area equivalent to more than 100 full Moons, or five degrees across on the sky. Blue highlights mature stars, while yellow and red show dust heated by massive newborn stars.

Read more about this image here: https://www.nasa.gov/mission_pages/WISE/multimedia/pia12832-c.html

The Large Magellanic Cloud

Image credits: Thomas Jarrett - based on WISE/NEOWISE data

Although the Andromeda galaxy is bigger, the Large Magellanic Cloud, a satellite galaxy of our Milky Way, is closer: "only" 160,000 light-years from Earth. This makes it appear larger than Andromeda on the sky, and it is easy to spot in the all-sky image at about 4 o'clock, halfway out from the galactic center. The central blue bar is light from older stars. An oddly square outline encompasses the orange clouds outside this bar, which are regions of dust and gas illuminated by younger stars.

Millions of Giant Black Holes

Image credits: NASA/JPL-Caltech/UCLA

Peering more than 10 billion light-years into the distance, WISE has found tens of millions of actively feeding supermassive lack holes across the full sky. The orange circles highlight those that the telescope identified in a small patch of sky; the two zoomed-in images came from the Hubble Space Telescope. WISE easily sees these monsters because their powerful, accreting black holes warm the dust, causing it to glow in infrared light. The blue circles indicate black holes that were detected using visible-light imagers. In most, that light is blocked by dust.

Read more about this image here: https://www.nasa.gov/mission_pages/WISE/multimedia/pia15481.html

The New Solar Neighborhood

Image credits: PSU/Cushing - based on WISE/NEOWISE data

WISE discoveries have redefined the solar neighborhood. The third- and fourth-closest systems to the Sun are brown dwarfs about 7 light-years away. Brown dwarfs form like stars but can't sustain the fusion that powers more massive stars. So they cool off with time and can be seen only in infrared light, which is invisible to the human eye. The WISE 0855-0714 system shown here is the coldest known - colder than ice. Very cold brown dwarfs appear only in the second-shortest wavelength band of WISE, as shown at bottom mapped to green.

Klotho and Lina

Image credits: NASA/JPL-Caltech/UCLA

Those aren't Klingon vessels. Appearing as strings of orange dots, the brightest sets of dots belong to asteroids Klotho and Lina. Both orbit out in the main asteroid belt between Mars and Jupiter, while smaller, more distant asteroids can also be seen passing through the image.

Comet 65P/Gunn

Image credits: NASA/JPL-Caltech/UCLA

What looks like a narwhal is actually comet 65P/Gunn, which orbits the Sun every 6.8 years. A comet is a ball of dust and ice left over from the formation of the solar system. As it approaches the Sun and heats up, its surface releases gas and dust, which are then blown back by the solar wind into a long, spectacular tail. The "sword" ahead of the comet's nucleus is made of dust particles shed by 65P/Gunn on previous orbits around the Sun.

Read more about this image here: https://www.nasa.gov/mission_pages/WISE/multimedia/gallery/13115-4x3.html

The Most Luminous Galaxy

Image credits: NRAO/AUI/NSF/S. Dagnello - based on WISE/NEOWISE data

The most luminous galaxy confirmed - discovered by WISE and known by its catalog number, WISE J224607.55-052634.9 - radiates with 350 trillion times the luminosity of the Sun. As illustrated in this artist's conception based on subsequent observations using the Atacama Large Millimeter/submillimeter Array in Chile, trails of dust are being pulled from three smaller galaxies into this blazing powerhouse. It appears to be cannibalizing its smaller neighbors, which is likely contributing to its superlative brightness. WISE discovered this galaxy as part of a rare population of objects that appear only in its longest wavelength bands.

Read more about this image here: https://www.jpl.nasa.gov/spaceimages/details.php?id=PIA22358

For more information about NEOWISE, visit:

https://www.nasa.gov/neowise

http://neowise.ipac.caltech.edu/

For more information about WISE, visit:

http://www.nasa.gov/wise

https://www.jpl.nasa.gov/wise/

Images, (mentioned), Text, Credits: NASA/Alana Johnson/JPL/DC Agle.

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