Once in a Blue Dune
Once in a Blue Dune
ESP_053894_2295  Science Theme: Seasonal Processes
Sand dunes often accumulate in the floors of craters. In this region of Lyot Crater there is a field of classic barchan dunes.

Just to the south of the group of barchan dunes is one large dune with a more complex structure. This particular dune, appearing like turquoise blue in enhanced color*, is made of finer material and/or has a different composition than the surroundings.

*NB: “Enhanced color” is also the same as false color, which we use to show details we cannot see in black and white. The dune is not actually blue and it would not look that way to our eyes if we were there. See the “About color products” link down below in the right-hand column.

Written by: Candy Hansen  (11 June 2018)

This is a stereo pair with ESP_053406_2295.
Acquisition date
24 January 2018

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
305.8 km (190.0 miles)

Original image scale range
34.7 cm/pixel (with 1 x 1 binning) so objects ~104 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
48°, with the Sun about 42° above the horizon

Solar longitude
119.8°, Northern Summer

For non-map projected images
North azimuth:  93°
Sub-solar azimuth:  344.6°
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   (1032MB)

IRB color
map-projected   (590MB)

Black and white
map-projected  (511MB)
non-map           (335MB)

IRB color
map projected  (167MB)
non-map           (268MB)

Merged IRB
map projected  (278MB)

Merged RGB
map-projected  (265MB)

RGB color
non map           (279MB)
Map-projected, reduced-resolution
Full resolution JP2 download
Anaglyph details page

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/JPL/University of Arizona

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.