Space Pictures This Week: Flaming Runaway, Moon Avalanche

Spinning Stars

Photograph by Babak Tafreshi, TWAN

The wheel of the cosmos turns behind the remains of a historic tower in Iran in a long-exposure picture taken this month.

The frame captures about three hours of stellar motion over the Alborz mountain range, which borders the southern end of the Caspian Sea (map). According to photographer Babak Tafreshi, towers such as this may have been used by ancient astronomers to maintain accurate calendars.

Published November 24, 2010

Putrid Sea

Image courtesy USGS and NASA Earth Observatory

Mineral salts make a network of lagoons shine like inlaid gems in a natural-color picture of Ukraine's Crimean Peninsula (map) taken by NASA's Landsat 5 orbiter and released this week. In the summer, the warmed marsh waters give off unpleasant odors, lending the region the nicknames "Rotten Sea" or "Putrid Sea."

Around the lagoons, boxy agricultural fields and circular irrigation systems turn the landscape into a geometric tapestry stitched together by curving highways. Part of the Black Sea is visible as a darker patch at lower left.

Published November 24, 2010

Runaway Star

Image courtesy NASA/JPL-Caltech/WISE Team

Like a hot-headed teenager, the star AE Aurigae is racing away from its birthplace after getting into a "fight" with its neighbors, as seen in a new picture from NASA's Wide-field Infrared Survey Explorer, or WISE, released Tuesday.

According to NASA, AE Aurigae was likely born in the Trapezium star cluster in the constellation Orion. At the time the star had a partner, making a binary pair with the star Mu Columbae. But about 2.5 million years ago, the pair collided with another set of binary stars, and the tussle sent AE Aurigae and Mu Columbae hurtling in opposite directions.

(Related: "'Renegade' Stars Tearing Across Universe, Hubble Shows.")

AE Aurigae is currently part of a relatively cool nebula that glows with only reflected light. But the star appears to be on fire, because the body's radiation is stripping electrons from a pocket of surrounding gas and heating nearby dust, causing the cloud to glow with its own emitted light.

Published November 24, 2010

Aurora, Interrupted

Photograph by Thilo Bubek

A lime green aurora seems to snake a tendril around the nearly full moon in the skies over Tromsø, Norway (map), in a long-exposure picture taken Tuesday.

The moon appears full when the lunar orb is on the opposite side of Earth from the sun, so that we see the fully illuminated disk. A moon that's more than half lighted and is on its way to becoming full is called a waxing gibbous moon.

Published November 24, 2010

Comet Bites the Dust

Image courtesy SOHO/STEREO/NASA

There's one fewer comet in our solar system, according to a new picture from NASA's Solar and Heliospheric Observatory released last week. The tiny comet seen above likely disintegrated sometime between November 13 and 14.

SOHO was able to spot the comet's approach by blocking out the sun's glare with a device called a coronagraph. The white circle inside the red disk created by the coronagraph represents the sun's actual size.

Published November 24, 2010

Lunar Avalanche

Image courtesy NASA/ASU

Dark material seems to ooze down the side of Robinson crater in a picture of the moon taken by NASA's Lunar Reconnaissance Orbiter. The image, released last week, shows a swath of land about 2,035 feet (620 meters) wide on the crater's northern slope.

The flows are thought to have been created by rock avalanches that long ago charged down the crater wall. Similar features on Mars have been interpreted as recent mudflows. It's unlikely liquid water ever existed on the moon's surface, though, so scientists think some of the Martian flow patterns might also be due to dry avalanches.

Published November 24, 2010