Click for movie.
During their normal use of Perseverance’s navigation cameras to survey upcoming terrain for future travel, the rover’s science team captured a short movie of a Martian dust devil as moved across a nearby ridgeline. I have annotated a still from that move above to indicate the dust devil.
The lower portion of a Martian dust devil was captured by one of the Navcams on NASA’s Perseverance rover on Aug. 30, 2023, the 899th Martian day, or sol, of the mission. The video, which has been enhanced in order to show maximal detail, was sped up 20 times and composed of 21 frames taken four seconds apart.
Using data from the imagery, mission scientists determined that the dust devil was about 2.5 miles (4 kilometers) away, at a location nicknamed “Thorofare Ridge,” and moving east to west at a clip of about 12 mph (19 kph). They calculated its width to be about 200 feet (60 meters). While only the bottom 387 feet (118 meters) of the swirling vortex are visible in the camera frame, scientists used the dust devil’s shadow to estimate its full height at about 1.2 miles (2 kilometers).
This Perseverance movie is not the first to catch a dust devil on the surface. Both Curiosity and Perseverance have done so previously, and I think the smaller earlier rovers Opportunity and Spirit did so as well. Nonetheless, this mini-twister provides more information about the atmosphere of Mars.
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