Space Pictures This Week: 3-D Sun Storm, Mars Devil

Aurora Over Iceland

Photograph by Tim Vollmer, My Shot

An aurora arches over Hveragerdi, Iceland, in a photo recently submitted to National Geographic's My Shot.

Auroras occur when large numbers of charged particles from the sun encounter Earth's magnetic shield. Most of these particles get corralled toward the Poles, where they slam into atmospheric gases such as nitrogen and oxygen.

(Also see "New Aurora Pictures: Earth-Shield Cracks Spur Surprises.")

Published March 12, 2012

"Surreal" Desert

Photograph courtesy NASA

Green fields dot a desert in northern Saudi Arabia in an "almost surreal" photograph taken from the International Space Station and released by the NASA Earth Observatory.

Over the past two decades, agriculture has come to the Wadi As-Sirhan Basin thanks to investment of oil-industry revenues by the Saudi government, according to NASA.

The fields are irrigated by water pumped from underground aquifers and distributed carefully via "center pivot" agriculture, which rotates water around a central point in a circular field. This targeted practice cuts down on wasting water, crucial in such an arid region.

In the picture, active fields, seen in both dark greens and browns, are about 0.62 mile (1 kilometer) wide.

(Also see "Underground 'Fossil Water' Running Out.")

Published March 12, 2012

Star Trails

Photograph by Kwon O. Chul, TWAN

Stars streak over illuminated fishing boats off Dokdo Island, South Korea, in a picture submitted to the astronomy-education project The World at Night (TWAN).

The fishers' lights wash out any starlight on the horizon—a common phenomenon worldwide.

Two-thirds of humanity lives under skies polluted with light, and one-fifth can no longer see the Milky Way, according to National Geographic magazine. (Read more about light pollution.)

Published March 12, 2012

Red-Planet Devil

Image courtesy U. Arizona/NASA

A dust devil casts a snake-like shadow over Mars in a "stunning" image released this week by the HiRISE camera team.

Martian dust devils, which can tower five to six miles (eight to ten kilometers) tall, form when summer heat gets the ground warmer than the air above it.

As warm air close to the ground rises, plumes of cooler air fall to replace it, creating vertical circulation. If a gust of wind blows through, it can send the circulating air spinning horizontally, triggering a dust devil.

The pictured dust plume's shadow suggests it reaches more than 0.5 mile (0.8 kilometer) high.

(See another picture of a Martian dust devil.)

Published March 12, 2012

Night Lights

Photograph courtesy NASA

Lights glimmer in the Mediterranean Sea region in an astronaut picture recently released by NASA.

Toward the left of the image, lights crowd the Nile River; its delta; and Alexandria, Egypt (top left center). The Gulf of Suez and the Suez Canal are seen to the right.

(See "Best Night-Sky Pictures of 2011 Named.")

Published March 12, 2012

Martian Canyon

Image courtesy G. Neukum, F.U.Berlin/DLR/ESA

A landslide-riddled part of the Martian canyon Ius Chasma is seen in a new image by the European Space Agency's High Resolution Stereo Camera.

Spanning 584 miles (940 kilometers), Ius Chasma forms the northern boundary between the western half of an enormous valley system called Valles Marineris and the Martian highlands.

In the same process that formed Earth's East African Rift, the Martian crust split and formed the gigantic canyon system, one of the solar system's largest.

(See "Pictures: Giant Mars Pits Revealed in Sharp Detail.")

Published March 12, 2012

More Space Pictures: Aurora, Hubble … Frazils? >>

Photograph by Yuichi Takasaka, TWAN

Published March 12, 2012