Crater photos show off dynamic Martian winds

Photos indicated the direction and recentness of wind on Mars.

New pictures from Mars show dust blowing out of a crater in the same area where NASA's rover Opportunity patrols, providing researchers with new data about Mars' dynamic weather system.

Taken by Europe's Mars Express probe in 2005 and released this week, the new Mars pictures show a 31-mile-wide (50-km) crater with black sand blowing out of the cavity. Mars Express used its High Resolution Stereo Camera (HRSC) to snap the latest red planet photos.

By looking at the dust trail, scientists can calculate the direction of the wind, which contributes to a better understanding of Martian weather at large, said Michael Wyatt, a professor of geological science at Brown University who worked with NASA on the Mars rovers.

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"If you know the direction of wind you can begin to understand weather dynamics," Wyatt said in a phone interview. "The wind on Mars is one of the most active processes for modifying the surface, and tells you a lot about the dynamics of the atmosphere."

In addition to showing wind direction, the picture also shows how recently a gust has blown across the crater, said Lori Fenton, a scientist the Carl Sagan Center who studies the wind patterns on Mars.

In 2003, a planet-wide dust storm deposited bright red grit across the entire surface. Since the black trail in the photo does not display any of that red dust, the black sand must have moved between the storm and when the HRSC snapped the photo, Fenton said.

"It's probably fairly recent, because there aren't any other craters or dust particles in the dark stuff," Fenton said in a phone interview.

Researchers have looked for clues about Martian weather in dust-strewn craters for decades, but few of those older images captured the detail and complexity exhibited in this most recent picture.

"People have studied these types of things for decades, and there are hundreds and hundreds of craters on Mars where people have studied wind streaks," Wyatt said. "But these are some of the most beautiful and detailed pictures I have ever seen of it."

That added detail allows researcher to see the effects of wind both inside and outside the crater, Fenton said.

While the dust blowing out of the crater clearly points in one direction, it appears that some of the black sand within in the crater has blown in another direction. This indicates wind swirling around inside the crater itself, Fenton said.

The crater rests in a Puerto Rico-sized area of Mars called the Meridiani Planum.

Observations of the Meridiani Planum showed an abundance of minerals associated with water. Water's relationship to both life and fascinating geological processes makes the area one of the most interesting sites on the planet, and a natural location for exploration by both the European Space Agency and NASA, Wyatt said.

• Gallery - Martian Photos From Mars Express
• Most Amazing Mars Rover Discoveries
• Mars as Seen by Spirit and Opportunity, Part 2

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