Known as a solar filament, the loop is a cloud of relatively cool gas held aloft by magnetic forces. Such features are unstable, though, and often break away from the sun.
The pictured filament grew extra long, according to NASA: It spanned almost 621,000 miles (a million kilometers) before snapping.
Image courtesy SDO/NASA
Flight of the Falcon
In what many are hailing as a coup for commercial spaceflight, the Falcon 9 rocket lifted off from Cape Canaveral on Wednesday and successfully carried the Dragon capsule into orbit. As planned, the capsule completed two orbits before splashing down in the Pacific.
Built by private firm SpaceX, the two vehicles are being tested for contracted use by NASA to carry supplies—and hopefully people—to the International Space Station after the space shuttles have been retired.
This week's test launch went off without a single hitch, according to SpaceX CEO Elon Musk, who described the feat as "just mind-blowingly awesome," the Associated Press reported.
Although it's not actually on fire, the nebula glows due to radiation from one of the three stars in Orion's belt, dubbed Alnitak. The star—seen as a blue dot to the right of the nebula's central region—causes gas in the nebula to become electrically charged, which makes it glow in visible light.
WISE's infrared eye, however, can see past the glow to capture the nebula's dust, which is also being warmed by light from Alnitak.
Image courtesy WISE/NASA
Seen at an angle by an astronaut aboard the International Space Station, several snow-covered volcanoes rise from Russia's Kamchatka Peninsula in a picture released Monday.
The most prominent peak is Kronotsky (center), a stratovolcano that last erupted in 1923. Stratovolcanoes are known for their steep, conical shapes, which are built by eruptions of viscous lava. By contrast, Schmidt (right) is a shield volcano, one with broad slopes built by fluid basalt lava. (See more volcano pictures.)
Photograph courtesy NASA
Curtains of Ice
Seen "upside down" in a picture from NASA's Cassini spacecraft, Saturn's moon Enceladus sprays jets of ice from the geysers at its south pole.
The unprocessed picture, released last week, is among several taken during Cassini's 12th flyby of the unusually active moon, completed November 30.
Image courtesy NASA
In the globular cluster M107, thousands of stars are packed into a space equal to 20 times the distance between the sun and its nearest stellar neighbor, Alpha Centauri. The swarm of ancient stars is the subject of a sharp, new picture released Thursday from the European Southern Observatory's facility in La Silla, Chile.
At more than ten billion years old, globular clusters are some of the oldest objects in the universe. M107 is a satellite of the Milky Way, so studying the swarm can give astronomers insight into the evolution of our home galaxy.
The stars are part of a brilliant cluster that was actually discovered two decades before the surrounding cloud of gas and dust from which they were born. Today the Eagle nebula is best known for a formation known as the Pillars of Creation (not pictured), which was featured in an iconic 1995 Hubble picture.
Image courtesy ESA/NASA
Scanning the Shuttle
Viewed from above, a backscatter device scans the space shuttleDiscovery's external fuel tank on December 2. The device bounces radiation off the tank, allowing technicians to see under the foam insulation.
Launch attempts for Discovery's next and final flight were scrubbed in early November when technicians found cracks in the foam, later shown to be linked to broken "ribs" under the insulation. NASA has since moved the launch attempt to February to make time for more safety tests.