A Sneak Peek into Saheki’s Secret Layers
A Sneak Peek into Saheki’s Secret Layers
ESP_049172_1585  Science Theme: Fluvial Processes
Saheki Crater is large, about 84 kilometers across, and located in the Southern highlands of Mars, to the north of Hellas Planitia. It’s filled with beautiful alluvial fans that formed when water (likely melting snow) carried fine material, such as sand, silt and mud, from the interior crater rim down to the bottom of the crater.

Two smaller craters impacted into the alluvial fan surface in Saheki, excavating holes that allow us to see what the fans look like beneath the surface. Exposed along the crater’s interior walls, we can see that the fan is made up of multiple individual layers (white and purple tones in the enhanced color image) that were deposited on the floor (the green and brown tones). The brown, circular shapes on the fan layers are small impact craters.

NB: North is down in the cutouts and wallpaper.

Written by: Sharon Wilson (narration: Tre Gibbs)  (4 April 2017)

This is a stereo pair with ESP_049528_1585.
Acquisition date
21 January 2017

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
258.0 km (160.4 miles)

Original image scale range
26.2 cm/pixel (with 1 x 1 binning) so objects ~78 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
30°, with the Sun about 60° above the horizon

Solar longitude
303.5°, Northern Winter

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  1.2°
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   (551MB)

IRB color
map-projected   (351MB)

Black and white
map-projected  (264MB)
non-map           (304MB)

IRB color
map projected  (98MB)
non-map           (292MB)

Merged IRB
map projected  (150MB)

Merged RGB
map-projected  (140MB)

RGB color
non map           (299MB)
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’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.