for National Geographic News
Using a classroom-size prop, a team of Dutch researchers says it may have demystified a handful of unusual Martian craters—and further complicated the story of the red planet's watery early years.
The team's new paper proposes that enormous amounts of water gushed out of the Martian interior and filled the oddly terraced craters in a torrent.
Each rare event would have lasted on the order of decades, not the centuries or millennia proposed for other water-carved features on the planet's surface.
"On Earth it would look like the Mississippi River or the Rhine River turning on from a single source and flowing for between ten and one hundred years and then just shutting off," said lead author Erin Kraal, who is now at Virginia Polytechnic Institute and State University.
Because there are no drainage networks on the surface of Mars, the study authors believe an unknown geological process triggered the huge releases of water.
(Related: "Mars Water Traces Left by Springs, Not Seas, Experts Say" [March 7, 2007].)
The findings, which are being met with a mix of excitement and skepticism, appear in tomorrow's issue of the journal Nature.
Among the many craters that characterize the Martian surface, some are basins with fan-shaped raised patterns at their bottoms.
Starting about three years ago, researchers began noticing that a handful of these fanned craters—ten so far—have a distinctive stair-like set of terraces.
But until now, how these odd patterns formed was a puzzle.
So Kraal, while working at her previous job in Utrecht University in the Netherlands, led a team that built an indoor flume that mimicked the Martian basins.
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