for National Geographic News
Odd materials recently found on Mars have planetary scientists scratching their heads.
That's because the materials were spotted at the red planet's equator—but they appear to contain a large amount of water like that previously seen only at the Martian poles.
The finding is based on new high-resolution radar data from the Martian subsurface, which show similarities between the properties of deposits on a hilly equatorial formation called Medusae Fossae and the sediments at the ice-rich poles.
Lead researcher Thomas Watters, of the Smithsonian Institution's National Air and Space Museum, said that the new data suggest two possible scenarios.
"We can't exclude the possibility that these deposits are dry, low-density materials," Watters said.
But the observed properties of the materials could also mean that the Martian equator is rich in ice.
Kenneth Tanaka, an astrogeologist with the U.S. Geological Survey (USGS) in Flagstaff, Arizona, said that the idea of ice on Mars's equator is somewhat shocking.
"It would be like finding evidence of ice caps on Earth at the Equator," Tanaka said. "It's kind of very strange."
Watters and colleagues describe the find in this week's issue of the online advance journal Science Express.
Watters' team examined the Martian surface using a radar instrument called MARSIS aboard the European Space Agency's Mars Express orbiter.
One of the team's areas of study was the Medusae Fossae Formation—a series of large, oddly textured plateaus at the equator that are covered with materials easily eroded by wind.
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