Anaglyph of East Mareotis Tholus
Anaglyph of East Mareotis Tholus
PSP_001760_2160  Science Theme: Volcanic Processes
East Mareotis Tholus is a small volcano in Tempe Terra, Mars. This area is on the northeast edge of the Tharsis bulge that was built up by many large and small volcanoes.

One of the many questions we hope to address with HiRISE is the relative roles of the giant shield volcanoes (such as Olympus Mons) and smaller volcanic features (such as East Mareotis Tholus).

The anaglyph covers 4.4 x 6.9 km (2.7 x 4.9 miles) and the topography can be viewed using red-blue glasses. The elongated pit at the summit of the volcano is where the lava issued forth. The large circular hole just to the SW of the vent is an impact crater. The gouges in the ground to the SE of the volcano are tectonic fissures (called graben) that are now filled with sand dunes. The area is covered with large amounts of wind-blown dust, so it is not surprising that lava flows and other smaller volcanic features are not visible.

However, the smooth shape of the volcano, and the lack of lava layers exposed in the impact crater, allow for the possiblity that this volcano is composed largely of ash, rather than lava flows.

Written by: Laszlo P. Keszthelyi  (17 January 2007)

This is a stereo pair with PSP_001364_2160.
Acquisition date
11 December 2006

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
288.0 km (179.0 miles)

Original image scale range
62.4 cm/pixel (with 2 x 2 binning) so objects ~187 cm across are resolved

Map projected scale
50 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
54°, with the Sun about 36° above the horizon

Solar longitude
148.8°, Northern Summer

For non-map projected images
North azimuth:  95°
Sub-solar azimuth:  353.4°
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   (165MB)

IRB color
map-projected   (82MB)

Black and white
map-projected  (77MB)
non-map           (61MB)

IRB color
map projected  (25MB)
non-map           (55MB)

Merged IRB
map projected  (140MB)

Merged RGB
map-projected  (144MB)

RGB color
non map           (52MB)
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.