Night Vision
Night Vision
ESP_044709_1275  Science Theme: Mass Wasting Processes
It’s hard to see in the dark. Most HiRISE images are are taken when the sun is at least 15 degrees above the horizon. (If you hold your hand at arm’s length with fingers together, it’s about five degrees wide on average.) However, to see what’s going on in winter, we need to look at times and places where the Sun is just barely over the horizon.

This image was taken to look at seasonal frost in gullies during southern winter on Mars, with the Sun only about two degrees over the horizon (just before sunset). To make things more difficult, the gullies are on a steep slope facing away from the sun, so they are in deep shadow. Under these conditions, HiRISE takes what are called “bin 4” images. This means that the image shows less detail, but by adding up the light from 16 pixels (a 4x4 square) we can see details in shadows.

Even with the reduced resolution, we can see plenty of detail in the gullies, and learn about the seasonal frost.

Written by: Colin Dundas (audio: Tre Gibbs)  (9 March 2016)
Acquisition date
09 February 2016

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
249.3 km (155.0 miles)

Original image scale range
99.9 cm/pixel (with 4 x 4 binning) so objects ~300 cm across are resolved

Map projected scale
100 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
88°, with the Sun about 2° above the horizon

Solar longitude
106.6°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  52.2°
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   (26MB)

IRB color
map-projected   (19MB)

Black and white
map-projected  (11MB)
non-map           (16MB)

IRB color
map projected  (4MB)
non-map           (19MB)

Merged IRB
map projected  (29MB)

Merged RGB
map-projected  (26MB)

RGB color
non map           (18MB)
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.