Collapse Pit in Tractus Fossae
Collapse Pit in Tractus Fossae
ESP_011386_2065  Science Theme: Volcanic Processes
This HiRISE image shows a collapse pit in Tractus Fossae, a region of large ridges and troughs created by tectonic activity.

The fossae occur on the Tharsis volcanic rise, a giant region of enhanced volcanic activity that includes the three large volcanoes Ascraeus Mons, Pavonis Mons and Arsia Mons.

The pit in this image has very steep walls, and so only a narrow arc is illuminated by sunlight. The rest of the pit is in dark shadow. However, a stretched version of the image shows details of the pit floor, due to a small amount of scattered sunlight.

Pits like this form by collapse into underground voids, such as those left by propagating magma-filled dikes. They may sometimes have overhanging walls, although in this case the walls can be seen and appear nearly vertical. Some similar features are found on Earth: Devil’s Throat, in Hawaii, is one example. Other similar examples have been imaged on Mars as well.

Written by: Colin Dundas  (9 March 2009)

This is a stereo pair with ESP_011531_2065.
Acquisition date
30 December 2008

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
280.0 km (174.0 miles)

Original image scale range
28.2 cm/pixel (with 1 x 1 binning) so objects ~85 cm across are resolved

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
61°, with the Sun about 29° above the horizon

Solar longitude
182.8°, Northern Autumn

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  347.4°
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
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RGB color
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Black and white
map-projected   (977MB)

IRB color
map-projected   (427MB)

Black and white
map-projected  (501MB)
non-map           (452MB)

IRB color
map projected  (140MB)
non-map           (378MB)

Merged IRB
map projected  (226MB)

Merged RGB
map-projected  (217MB)

RGB color
non map           (371MB)
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.