Register for an account


Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.


Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

The Sciences

#40: Wild Winds Made Mars Gorgeous

By Valerie RossDecember 16, 2010 6:00 AM
NASA/CalTech/JPL/E.DeJong/J.Craig/M.Stetson | NULL


Sign up for our email newsletter for the latest science news

Mars has a wispy atmosphere, with just 0.006 times the surface pressure of Earth. But that is enough to have sculptured one of the most dramatic landscapes in the solar system, University of Texas geophysicist Jack Holt reported in May. The ice cap of Mars’s north pole is marked with enormous gorges; the largest, Chasma Boreale (jutting upward at right), is deeper and wider than the Grand Canyon. For four decades scientists debated how these canyons formed. Using the Shallow Radar instrument aboard NASA’s Mars Reconnaissance Orbiter, Holt was able to peek beneath the ice’s surface for clues; in particular, the radar could pick out differences in electrical reflectivity between overlying layers, showing how the ice built up over time. The data reveal that as the northern ice cap grew, its changing contours altered local wind patterns. Over millions of years, the weak but persistent winds ate away at the surface ice and dust, carving out Chasma Boreale in all its glory.

    3 Free Articles Left

    Want it all? Get unlimited access when you subscribe.


    Already a subscriber? Register or Log In

    Want unlimited access?

    Subscribe today and save 70%


    Already a subscriber? Register or Log In