CalTech NASA JPL JPL CalTech
NASA Logo - Jet Propulsion Laboratory Follow this link to skip to the main content
   + View the NASA Portal

JPL Home Earth Solar System Stars & Galaxies Technology
Mars Exploration Rovers
Images Multimedia News Missions Events Kids Education Science & Research About JPL
At a Glance
Daily Updates
Flight Director Reports
News Releases
Features
Image Releases
Multimedia
Fact Sheet
Press Kit
Media Contacts
Link to MER Home Page

 Popular Images:
 + Raw Images
 + Artist's Concept
 + Mars Wallpapers

 Image Archives:
 + May 2011
 + April 2011
 + March 2011
 + February 2011
 + January 2011
 + December 2010
 + November 2010
 + October 2010
 + September 2010
 + August 2010
 + July 2010
 + June 2010
 + May 2010
 + April 2010
 + March 2010
 + February 2010
 + January 2010
 + December 2009
 + November 2009
 + October 2009
 + September 2009
 + August 2009
 + July 2009
 + June 2009
 + May 2009
 + April 2009
 + March 2009
 + February 2009
 + January 2009
 + December 2008
 + November 2008
 + October 2008
 + September 2008
 + August 2008
 + July 2008
 + June 2008
 + May 2008
 + April 2008
 + March 2008
 + February 2008
 + January 2008
 + December 2007
 + November 2007
 + October 2007
 + September 2007
 + August 2007
 + July 2007
 + June 2007
 + May 2007
 + April 2007
 + March 2007
 + February 2007
 + January 2007
 + December 2006
 + November 2006
 + October 2006
 + September 2006
 + August 2006
 + July 2006
 + June 2006
 + May 2006
 + April 2006
 + March 2006
 + February 2006
 + January 2006
 + December 2005
 + November 2005
 + October 2005
 + September 2005
 + August 2005
 + July 2005
 + June 2005
 + May 2005
 + April 2005
 + March 2005
 + February 2005
 + January 2005
 + December 2004
 + November 2004
 + October 2004
 + September 2004
 + August 2004
 + July 2004
 + June 2004
 + May 2004
 + April 2004
 + March 2004
 + February 2004
 + January 2004
 + 2003
 + 2002

 Site Tools:
 + Adobe Reader
 + Apple QuickTime
 + Macromedia Flash
 + RealPlayer
Dust Devils near Gusev Crater

Gusev Dust Devil Movie, Sol 459 (Enhanced)
4/21/05
This movie clip shows a dust devil scooting across a plain inside Gusev Crater on Mars as seen from the NASA rover Spirit's hillside vantage point during the rover's 459th martian day, or sol (April 18, 2005). The individual images were taken about 20 seconds apart by Spirit's navigation camera, and the contrast has been enhanced for anything in the images that changes from frame to frame, that is, for the dust devil.

The movie results from a new way of watching for dust devils, which are whirlwinds that hoist dust from the surface into the air. Spirit began seeing dust devils in isolated images in March 2005. At first, the rover team relied on luck. It might catch a dust devil in an image or it might miss by a few minutes. Using the new detection strategy, the rover takes a series of 21 images. Spirit sends a few of them to Earth, as well as little thumbnail images of all of them. Team members use the 3 big images and all the small images to decide whether the additional big images have dust devils. For this movie, they specifically told Spirit to send back frames that they knew had dust devils.

The images were processed in three steps. All images were calibrated to remove known camera artifacts. The images were then processed to remove stationary objects. The result is a gray scene showing only features that change with time. The final step combined the original image with the image that shows only moving features, showing the martian scene and the enhanced dust devils.

Scientists expected dust devils since before Spirit landed. The landing area inside Gusev Crater is filled with dark streaks left behind when dust devils pick dust up from an area. It is also filled with bright "hollows", which are dust-filled miniature craters. Dust covers most of the terrain. Winds flow into and out of Gusev crater every day. The Sun heats the surface so that the surface is warm to the touch even though the atmosphere at 2 meters (6 feet) above the surface would be chilly. That temperature contrast causes convection. Mixing the dust, winds, and convection should trigger dust devils.

Scientists will use the images to study several things. Tracking the dust devils tells which way the wind blows at different times of day. Statistics on the size of typical dust devils will help with estimates of how much dust they pump into the atmosphere every day. By watching individual dust devils change as they go over more-dusty and less-dusty terrain, researchers can learn about the turbulent motion near the surface. Ultimately, that motion of wind and dust near the surface relates these small dust devils with Mars' large dust storms.

Image Credit: NASA/JPL

+ Related animation
+ Medium resolution version of this image
+ High resolution version of this image
+ Print this image and caption
Privacy / Copyrights FAQ Contact JPL Sitemap
FIRST GOV + Freedom of Information Act NASA Home Page
Site Manager:
Webmasters:
  Susan Watanabe
Tony Greicius, Martin Perez