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6 March 2014 1:04 pm ,
Vol. 343 ,
Magdalena Koziol, a former postdoc at Yale University, was the victim of scientific sabotage. Now, she is suing the...
Antiretroviral drugs can protect people from becoming infected by HIV. But so-called pre-exposure prophylaxis, or PrEP...
Two studies show that eating a diet low in protein and high in carbohydrates is linked to a longer, healthier life, and...
Considered an icon of conservation science, researchers at World Wildlife Fund (WWF) headquarters in Washington, D.C.,...
The new atlas, which shows the distribution of important trace metals and other substances, is the first product of...
Early in April, the first of a fleet of environmental monitoring satellites will lift off from Europe's spaceport in...
Since 2000, U.S. government health research agencies have spent almost $1 billion on an effort to churn out thousands...
- 6 March 2014 1:04 pm , Vol. 343 , #6175
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ScienceShot: Mystery of Mars Polar Pinwheel Unraveled
26 May 2010 1:09 pm
Something strange has happened to Mars's polar ice cap. Instead of a uniform, roughly circular blob, like on Earth, the Martian version resembles a pinwheel (left), with dry, spiral troughs separating the ice sheets. There's also Chasma Boreale, the deep, dagger-shaped gouge that cuts across the pinwheel. Scientists had thought that the canyon, which is 2 kilometers deep, was carved by some catastrophic flood in the distant past. Now in two papers published tomorrow in Nature, researchers think they have solved both mysteries. Using a radar survey of the pole (right), which peered under the ice, they conclude that Chasma Boreale wasn't dug out at all. Instead, Martian winds built up the steep, canyon-like walls over millions of years. As for the pinwheel, the team reports that it likewise formed over many millennia, as strong winds pushed apart the dry ice crystals on the surface, much like winds on Earth create sand dunes.
See more ScienceShots.