Space Pictures This Week: Solar Chicken, Aurora Angel, More

Galaxy-Rise

Photograph by Jack Fusco, My Shot

Star trails trace the path of the Milky Way as it rises over the shore of Strathmere, New Jersey, in a long-exposure picture taken last week.

Published April 26, 2012

Frosty Dunes

Image courtesy U. Arizona/NASA

It might look as if someone sculpted a pigeon in the Martian sand. But this newly released image from NASA's Mars Reconnaissance Orbiter shows naturally shaped dunes in the red planet's north polar region, which are lined and speckled by defrosting winter ice.

White regions indicate where fine-grained frost still rims the polar dunes. Dark blotches, meanwhile, are most likely made from sediment kicked up by carbon dioxide "geysers" created as ice layers sublimate, or turn directly from a solid to a gas.

Published April 26, 2012

Split Galaxy

Image courtesy Caltech/NASA

In visible light the Sombrero galaxy resembles a wide-brimmed hat, with a disk topped by a large central bulge of stars. But new infrared views from NASA's Spitzer Space Telescope now reveal that the bulge contains enough mass for astronomers to classify it as an elliptical galaxy.

The finding means that the Sombrero is the first known galaxy to display features of two galactic types: thin disks and rotund ellipticals. Researchers say it's unlikely the "split personality" galaxy formed via a merger, since the violent collision would have destroyed the disk shape.

Instead, the team proposes that the Sombrero could have formed when an elliptical galaxy swallowed bunches of gas clouds, which fell into orbit around the galactic center and formed a flat disk of star-forming material.

Published April 26, 2012

Angelic Aurora

Photograph by Babak Tafreshi, TWAN

A multicolored aurora spreads like angel wings over a traditional Sami village in Lapland, northern Sweden, as seen in a recently released picture.

The vivid greens and purples are created when charged solar particles collide with oxygen and hydrogen high in Earth's atmosphere. The affected air molecules are infused with extra energy, which they release as light.

Published April 26, 2012

Smoking Cluster

Image courtesy ESO

The star cluster known as NGC 6604 glitters within glowing hydrogen gas in a new picture from a European Southern Observatory telescope in La Silla, Chile.

The young star cluster contains an example of a "chimney"—a mysterious column of hot, charged gas that seems to funnel material away from star clusters.

At about 5,500 light-years away, NGC 6604 sits relatively close to Earth, which means astronomers can study its chimney in detail.

Published April 26, 2012

Hubble's Egg

Image courtesy ESA/NASA

Beams of light shine through the thick cloud of dust at the center of the Egg nebula, one of the few known examples of a preplanetary nebula—a rarely seen phase in the life cycle of sunlike stars.

The new image combines visible and infrared light captured by the Hubble Space Telescope to offer one of the best views yet of the Egg.

When stars around the same mass as our sun run out of nuclear fuel, they swell and begin ejecting their outer layers of gas. Over a few thousand years, the hot stellar core heats up the surrounding cloud of dust and gas, causing it to glow as a planetary nebula.

A preplanetary nebula is a relatively short-lived stage in this process, when the dying star is still shrouded in a cocoon of opaque dust. In the case of the Egg, astronomers think polar jets from the star are carving holes in the dense dust cloud, allowing some light to escape.

Published April 26, 2012

Shifting Sands

Image courtesy Jesse Allen and Robert Simmon, Landsat/USGS/NASA

A rise of rocky land cuts like a scar through the Empty Quarter, the world's largest sand sea, in a newly released picture from NASA's Landsat 7 satellite.

Roughly the size of France, the Empty Quarter covers parts of Saudi Arabia, Yemen, Oman, and the United Arab Emirates. This frame shows the town and airport of Sharurah, just north of the Saudi Arabia-Yemen border, near the tip of the rocky rise.

Published April 26, 2012

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Image courtesy SDO/NASA

Published April 26, 2012