The Space Shuttle Endeavour lands safely in Florida.
With landing gear down, space shuttle Endeavour approaches the Shuttle Landing Facility at NASA's Kennedy Space Center in Florida after 14 days in space, completing the 5.7-million-mile STS-130 mission. Endeavour landed at 10:20 p.m. EST on Sunday, Feb. 21, after delivering the new Tranquility node and its seven-window cupola to the International Space Station. Returning to Earth aboard Endeavour are Commander George Zamka; Pilot Terry Virts; and Mission Specialists Robert Behnken, Nicholas Patrick, Kathryn Hire and Stephen Robinson. Credit: NASA.
This photograph, taken Feb. 21, 2010 by Japanese astronaut Soichi Noguchi, shows the space shuttle Endeavour performing an S-turn to slow its speed during landing, as seen from 220 miles up from the station's new Cupola lookout. Credit: Soichi Noguchi via Twitter.
The sun rises over the limb of the Earth in this photo taken from the International Space Station's new Cupola observation deck on Feb. 18, 2010. A Russian Progress spacecraft, docked to the Pirs Docking Compartment, is visible at right. Credit: NASA.
The immense Andromeda galaxy, also known as Messier 31 or simply M31, is captured in full in this new image from NASA's Wide-field Infrared Survey Explorer, or WISE. The mosaic covers an area equivalent to more than 100 full moons, or five degrees across the sky. WISE used all four of its infrared detectors to capture this picture (3.4- and 4.6-micron light is colored blue; 12-micron light is green; and 22-micron light is red). Blue highlights mature stars, while yellow and red show dust heated by newborn, massive stars.
Andromeda is the closest large galaxy to our Milky Way galaxy, and is located 2.5 million light-years from our sun. It is close enough for telescopes to spy the details of its ringed arms of new stars and hazy blue backbone of older stars. Also seen in the mosaic are two satellite galaxies, known as M32, located just a bit above Andromeda to the left of center, and the fuzzy blue M110, located below the center of the great spiral arms. These satellites are the largest of several that are gravitationally bound to Andromeda.
The Andromeda galaxy is larger than our Milky Way and contains more stars, but the Milky Way is thought to perhaps have more mass due to its larger proportion of a mysterious substance called dark matter. Both galaxies belong to our so-called Local Group, a collection of more than 50 galaxies, most of which are tiny dwarf systems. In its quest to map the whole sky, WISE will capture the entire Local Group. Credit: NASA/JPL-Caltech/UCLA.
This image from NASA's Wide-field Infrared Survey Explorer, or WISE, highlights the Andromeda galaxy's older stellar population in blue. It was taken by the shortest-wavelength camera on WISE, which detects infrared light of 3.4 microns. A pronounced warp in the disk 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. Credit: NASA/JPL-Caltech/WISE
This image from NASA's Wide-field Infrared Survey Explorer, or WISE, highlights the dust that speckles the Andromeda galaxy's spiral arms. It shows light seen by the longest-wavelength infrared detectors on WISE (12-micron light has been color coded orange, and 22-micron light, red).
The hot dust, which is being heated by newborn stars, traces the spidery arms all the way to the center of the galaxy. Telltale signs of young stars can also be seen in the centers of Andromeda's smaller companion galaxies, M32 and M110.
Andromeda, also called M31, is 2.5 million light-years away, and is the nearest large neighbor to our Milky Way galaxy. Credit: NASA/JPL-Caltech/UCLA
Comet Siding Spring appears to streak across the sky like a superhero in this new infrared image from NASA's Wide-field Infrared Survey Explorer, or WISE. The comet, also known as C/2007 Q3, was discovered in 2007 by observers in Australia.
The snowball-like mass of ice and dust spent billions of years orbiting in the deep freeze of the Oort Cloud, a spherical cloud of comets surrounding our solar system. At some point, it got knocked out of this orbit and onto a course that brings it closer to the sun. On October 7, 2009, it passed as close as 1.2 astronomical units from Earth and 2.25 astronomical units from the sun (an astronomical unit is the distance between the sun and Earth). Now, the comet is leaving the warmer, more hospitable neighborhood of the solar system and heading back out to chillier parts.
In this view, longer wavelengths of infrared light are red and shorter wavelengths are blue. The comet appears red because it is more than ten times colder than the surrounding stars, for example, the bright blue star in the foreground. Colder objects give off more of their light at longer wavelengths. An ice cube, for example, pours out a larger fraction of its light at longer infrared wavelengths than a cup of hot tea emits.
A comet like this one can be thought of as a time capsule leftover from the formation of our solar system 4.5 billion years ago. After spending most of its long, lonely life in the darkest, coldest parts of our solar system, it warms up as it approaches the sun. The sunlight causes it to shed ices and dust in a long tail that trails behind it.
Comet Siding Spring, having experienced this "spring" awakening, is glowing in infrared light that WISE can see. Once it moves too far from the sun's warmth and light, it will disappear from view for the foreseeable future.
Astronomers will use these measurements to learn about the comet's size, composition, reflectivity, and the size and makeup of the dust particles in its coma (the hazy cloud surrounding its nucleus) and its tail. WISE data on this and other comets will help unlock clues that lay within these icy time capsules, teaching us about our solar system's evolution.
In this image, 3.4-micron light is colored blue; 4.6-micron light is green; 12-micron light is orange; and 22-micron light is red. It was taken on Jan. 10, 2010. Credit: NASA/JPL-Caltech/UCLA.