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NASA Mars Orbiter Catches Twister in Action |
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NASA Mars Orbiter Catches Twister in
Action
March 07, 2012
An afternoon whirlwind on Mars lofts a twisting column of dust more than half a mile (800 meters) high in an image
from the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter.
HiRISE captured the image on Feb. 16, 2012, while the orbiter passed over the Amazonis Planitia region of northern
Mars. In the area observed, paths of many previous whirlwinds, or dust devils, are visible as streaks on the dusty
surface.
A towering dust devil casts a serpentine shadow over the Martian surface in
this image acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars
Reconnaissance Orbiter. Image credit: NASA/JPL-Caltech/Univ. of Arizona
› Full image and caption
The active dust devil displays a delicate arc produced by a westerly breeze partway up its height. The dust
plume is about 30 yards or meters in diameter.
The image was taken during the time of Martian year when
that planet is farthest from the sun. Just as on Earth, winds on Mars are powered by solar heating. Exposure to
the sun's rays declines during this season, yet even now, dust devils act relentlessly to clean the surface of
freshly deposited dust, a little at a time.
Dust devils occur on Earth as well as on Mars. They are
spinning columns of air, made visible by the dust they pull off the ground. Unlike a tornado, a dust devil
typically forms on a clear day when the ground is heated by the sun, warming the air just above the ground. As
heated air near the surface rises quickly through a small pocket of cooler air above it, the air may begin to
rotate, if conditions are just right.
The Mars Reconnaissance Orbiter has been examining Mars with six
science instruments since 2006. Now in an extended mission, the orbiter continues to provide insights into the
planet's ancient environments and how processes such as wind, meteorite impacts and seasonal frosts continue to
affect the Martian surface today. This mission has returned more data about Mars than all other orbital and
surface missions combined.
More than 21,700 images taken by HiRISE are available for viewing on the
instrument team's website: https://hirise.lpl.arizona.edu
. Each observation by this telescopic camera covers several square miles, or square kilometers, and can reveal
features as small as a desk.
HiRISE is operated by the University of Arizona, Tucson. The instrument was
built by Ball Aerospace & Technologies Corp., Boulder, Colo. The Mars Reconnaissance Orbiter Project and the Mars
Exploration Rover Project are managed by the Jet Propulsion Laboratory, Pasadena, Calif., for NASA's Science
Mission Directorate, Washington. JPL is a division of the California Institute of Technology, also in Pasadena.
Lockheed Martin Space Systems, Denver, built the orbiter. For more about the Mars Reconnaissance Orbiter, see
www.nasa.gov/mro.
Guy Webster 818-354-6278
Jet Propulsion Laboratory, Pasadena, Calif.
guy.webster@jpl.nasa.gov
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