On January 14, NASA's Wide-field Infrared Survey Explorer (WISE) began a scan of the full sky using infrared light. Since then, it has sent back more than a quarter-million raw images. Now, NASA has released six sample images, including "a wispy comet, a bursting star-forming cloud, the grand Andromeda galaxy, and a faraway cluster of hundreds of galaxies."
One purpose of the mission is to try to locate dozens of new comets, "including some that ride along in orbits that take them somewhat close to Earth's path around the sun," NASA said. As well, it is hoped that the telescope will identify asteroids and cool stars known as brown dwarfs.
All told, the telescope is expected to complete a scan-and-a-half of the entire sky before the frozen coolant required to chill its equipment is exhausted this October.
In this image, taken by WISE, a comet called Sliding Spring seems to shoot across the sky. First discovered by Australians in 2007, Sliding Spring is also called C/2007 Q3.
Comet Sliding Spring passed as close as 1.2 astronomical units from Earth on October 7, 2009, according to NASA, after spending billions of years in the so-called Oort Cloud, a spherical collection of comets outside our solar system. Eventually, it was redirected outside the cloud.
NASA/JPL-Caltech/UCLA and NASA/STScI/MPIA/Univ. of Heidelberg/Univ. of Illinois at Urbana-Champaign
Here, we see a star-forming cloud overflowing with massive new stars, as well as gas and dust. In the inset, according to NASA, we can see the true center of the cloud, a group of stars known as NGC 3603.
NASA explained that WISE is "particularly sensitive to the warm dust that permeates star-forming clouds like this one."
One element of the WISE mission is that it complements other telescopes, such as Hubble, by offering context for far more detailed investigation. The larger WISE image seen here is 2,500 times bigger than the inset, from Hubble.
This cluster has some of the biggest stars yet discovered in it. "Winds and radiation from the stars are evaporating and dispersing the cloud material from which they formed," according to NASA, "warming the cold dust and gas surrounding the central nebula."
One result of this imagery is circumstantial evidence that the huge stars in the middle of the cluster caused the creation of younger stars in the cluster's "halo," which appear here as red dots. At the same time, the dust in the center is at an extremely high temperature, making large amounts of infrared light. That leads to the "bright, yellow cores of the nebulosity."
The famous Andromeda Galaxy, also called Messier 31, or M31, is seen in all its glory here. NASA's WISE telescope used each of its four infrared detectors to take this mosaic, which spans an area equal to more than 100 full moons, or five degrees across the sky.
In the image, the blue colors represent mature stars, and yellow and red highlight dust heated by new, giant stars.
As a galaxy, Andromeda is our closest neighbor, found just 2.5 million light-years from us. Telescopes are able to spot the details on its "ringed arms of new stars and hazy blue backbone of older stars," according to NASA. The image also includes two additional galaxies, M32, just a bit above and to the left of Andromeda's center, as well as M10, found below the spiral arms' center. Of a number of galaxies that are gravitationally linked to Andromeda, these are the largest.
Andromeda is bigger than the Milky Way and has more stars, NASA said. But our galaxy likely has greater mass because of a vast amount of what's called dark matter.
Dirt on Andromeda
This WISE image showcases "the dust that speckles the Andromeda galaxy's spiral arms," according to NASA. The superheated dust, which has had its temperature raised by newborn stars, follows the spidery arms towards the galaxy's center.
In this WISE image, we see Andromeda's older stars in blue. "A pronounced warp in the disc of the galaxy, the aftermath of a collision with another galaxy, can be clearly seen in the spiral arm to the upper left side of the galaxy," said NASA.
Fornax Galaxy Cluster
Here, we see an image of a densely-packed galaxy cluster known as Fornax. It is 60 million light-years from Earth, yet is one of our closest galaxy cluster neighbors.