Aerosols in the Air
Aerosols in the Air
ESP_020163_0980  Science Theme: Seasonal Processes
HiRISE images are monochromatic across much of the scene, but in the center we return color data. The color strip down the center of this image gives us insight into aerosols (particles of dust and frost) suspended in the atmosphere and the seasonal processes that get them there.

In the winter Mars’ south polar region is covered by a layer of carbon dioxide ice (dry ice). In the spring this ice evaporates from the top and the bottom of the seasonal ice layer (typically tens of centimeters thick). Where there are cracks in the ice the gas from below escapes, carrying fine particles from the surface up to the top of the ice. Larger particles fall back onto the ground in fan-shaped deposits pointing in a direction determined by the local winds.

We see the smaller particles (dust) suspended in the air locally over the cracks as the bluish tone over the regions with fans. Over regions without fans, where gas and dust from the surface are not escaping into the atmosphere, the surface is a more pinkish tone.

Written by: Candy Hansen  (5 January 2011)
Acquisition date
14 November 2010

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
248.2 km (154.3 miles)

Original image scale range
99.4 cm/pixel (with 4 x 4 binning) so objects ~298 cm across are resolved

Map projected scale
100 cm/pixel

Map projection

Emission angle

Phase angle

Solar incidence angle
87°, with the Sun about 3° above the horizon

Solar longitude
181.1°, Northern Autumn

For non-map projected images
North azimuth:  110°
Sub-solar azimuth:  35.3°
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

Black and white
map-projected   (102MB)

IRB color
map-projected   (56MB)

Black and white
map-projected  (67MB)
non-map           (72MB)

IRB color
map projected  (38MB)
non-map           (67MB)

Merged IRB
map projected  (114MB)

Merged RGB
map-projected  (106MB)

RGB color
non map           (65MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

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

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’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.