Waiting for Dust Devils
NASA/JPL-Caltech/UArizona
Waiting for Dust Devils
ESP_036376_2160  Science Theme: Aeolian Processes
HiRISE has captured some stunning images of dust devils in action, but the overall sample remains fairly limited. Both Mars Orbiter Camera and HiRISE images in this general region have a fairly high rate of capturing dust devils (sometimes several in one image), so acquiring images here in the right season has a good chance to help us obtain better measurements of these features.

This image has been fairly successful, showing one well-defined, large dust devil in the north and two less well formed ones in the center. Dust devils are identified in images both by their cloudy form and the shadow their cloud casts on the surface, from which the height of the dust devil can be determined.

Dust devils on Mars form the same way they do in deserts on Earth: strong heating of the surface by the sun, rising of heated, less-dense air that swirls upwards in a column, some wind to move it along a path over the ground, and entrainment, or picking up, of surface particles such as dust.

Preliminary results have shown that the along-ground movement and the circulating winds of a dust devil can be estimated using the HiRISE color frames if the dust devils happen to be imaged in the HiRISE color swath (down the center of the image).

Written by: HIRISE Science Team  (18 June 2014)
 
Acquisition date
30 April 2014

Local Mars time
15:20

Latitude (centered)
35.446°

Longitude (East)
201.999°

Spacecraft altitude
295.9 km (183.9 miles)

Original image scale range
59.5 cm/pixel (with 2 x 2 binning) so objects ~178 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection
Equirectangular

Emission angle
5.7°

Phase angle
51.7°

Solar incidence angle
46°, with the Sun about 44° above the horizon

Solar longitude
124.0°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  1.5°
JPEG
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

JP2
Black and white
map-projected   (459MB)

IRB color
map-projected   (261MB)

JP2 EXTRAS
Black and white
map-projected  (238MB)
non-map           (237MB)

IRB color
map projected  (115MB)
non-map           (213MB)

Merged IRB
map projected  (455MB)

Merged RGB
map-projected  (460MB)

RGB color
non map           (202MB)
ADDITIONAL INFORMATION
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products
HiView

NB
IRB: infrared-red-blue
RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

USAGE POLICY
All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible:
NASA/JPL-Caltech/UArizona

POSTSCRIPT
NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA’s Science Mission Directorate, Washington. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.