Christopher Columbus rode the trade winds from Europe to America. But on Saturn's moon Titan, a wind-driven westward voyage might not be possible. A new map of Titan'srndunes reveals that near-surface winds at the equator blow the wrong way: from west to east. That's the opposite of the predictions made by models of Titan's atmosphere. Researchers say there's no clear path to'reconciling those differences.rnFor the map, published in Geophysical Research Letters last month, planetary scientists Ralph Lorenz of Johns Hopkins University in Laurel, Maryland, and Jani Radebaugh of Brigham Young University in Provo, Utah, used images from the Synthetic Aperture Radar instrument on the Cassini spacecraft to map 16,000 individual dune segments, equivalent to 8% of Titan's surface. The dunes, all within 30° latitude of the equator, roughly align along an east-west axis. From the way the dunes divert around obstacles, the scientists inferred that the winds that formed them must have come from the west, Radebaugh says.
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