- News Home
17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
- About Us
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.