Mars Global Surveyor
Mars Orbiter Camera

Mars Orbiter Camera (MOC) High and Low Resolution Images
SPO-2 Observations:

Elysium Mons Volcano


Mars Global Surveyor Mars Orbiter Camera Release:          MOC2-57a, -57b, -57c, -57d, -57e, -57f, -57g, -57h
Mars Global Surveyor Mars Orbiter Camera Image ID:         583905525.40301 
                                                           P403-01 (Red WA);
							   P403-02 (Blue WA);
							   P403-03 (Hi. Res. NA) 
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(A) Elysium Volcanic Region as seen by MOC on July 2, 1998. Volcano near top center is Hecates Tholus--note bright clouds off its northeast flank. Volcano near center is Elysium Mons; volcano toward lower right is Albor Tholus. Red channel is MOC red wide angle image 40301, the blue channel is MOC blue wide angle image 40302, and the green channel is synthesized by averaging the red and blue bands. Image is an orthographic projection centered at 24.85°N, 213.25°W. The scale at the center of the projection is 4.65 kilometers (2.9 miles) per pixel. North is up, illumination is from the lower right.

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(B) Mariner 9 view of Elysium Mons taken on October 16, 1972, at 11:37 a.m. PST. This is a mosaic of images 676B01 and 676B02 (where the numbers before the "B" refer to the Mariner 9 orbit on which the images were taken, the "B" refers to the Mariner 9 high resolution camera, and the last two digits indicate the image number on that orbit). North is up, illumination is from the right. Reproduced in a simple cylindrical projection at a scale of 75 m/pixel.

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(C) Anaglyph stereo image of Elysium Mons (use red filter for left eye), constructed from Mariner 9 high resolution B-frame images. Two images were taken 9 months apart by Mariner 9 in 1972 to provide this high-resolution, stereoscopic view of the summit of Elysium Mons. The first image (134B31), acquired on January 19, 1972, at 4:12 p.m. PST, was taken at a viewing angle of 19° from vertical, while the second image (676B01) was acquired on October 16, 1972, at 11:37 a.m. PST. The image scale is roughly 80 m/pixel.

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(D) Comparison of Elysium Mons summit and upper flanks with the summit and flanks of Emi Koussi volcano in Chad on the continent of Africa. The Elysium Mons picture is from Mariner 9, the Emi Koussi picture was taken by an astronaut on Apollo 7 (Frame # 5-1621) in 1968. The two volcanoes show many similarities. Both have an approximately circular caldera-- the central crater at the summit-- with evidence of two caldera collapse events. Both have deep channels incised into the caldera rim and upper flanks--the channels developed as a result of faulting followed by lava which poured through them. The two volcanoes are different in one important aspect, however--water runoff (e.g., from rain) has formed many channels on the lower flanks of Emi Koussi, but no such channels formed on Elysium Mons (i.e., it never rained on Elysium Mons). This figure and further details on the comparison of these two volcanoes were published by MOC Principal Investigator Michael C. Malin, "Comparison of volcanic features of Elysium (Mars) and Tibesti (Earth)," Geological Society of America Bulletin, v. 88, p. 908-919, 1977.

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(E) Elysium Mons summit region. White box shows location of MOC narrow angle image 40303 (below). Base map is U.S. Geological Survey Viking photomosaic at 1:256 scale. North is up, illumination is from the left.

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(F) MOC image 40303, shown at 25% of its original size. North is approximately up, illumination is from the right. Resolution of picture shown here is 21 meters (69 feet) per pixel. Image was received with bright slopes saturated at DN=255.

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(G) MOC image 40303, shown at 25% of its original size, same as above in (F), except shown here with a box that indicates the location of the full-resolution subframe shown below in (H).

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(H) MOC image 40303 subframe of the Elysium Mons' southern caldera wall and floor shown at full resolution (5.24 meters (17.2 feet) per pixel). Illumination is from the right, north is approximately up.

You may need to adjust the images for the gamma of your monitor to insure proper viewing.

Note: This MOC image is made available in order to share with the public the excitement of new discoveries being made via the Mars Global Surveyor spacecraft. The image may be reproduced only if the image is credited to "Malin Space Science Systems/NASA". Release of this image does not constitute a release of scientific data. The image and its caption should not be referenced in the scientific literature. Full data releases to the scientific community are scheduled by the Mars Global Surveyor Project and NASA Planetary Data System. Typically, data will be released after a 6 month calibration and validation period.

Click Here for more information on MGS data release and archiving plans.


On July 4, 1998---the first anniversary of the Mars Pathfinder landing--- Mars Global Surveyor's latest images were radioed to Earth with little fanfare. The images received on July 4, 1998, however, were very exciting because they included a rare crossing of the summit caldera of a major martian volcano.

Elysium Mons is located at 25°N, 213°W, in the martian eastern hemisphere. As shown in Figure (A), above, Elysium Mons is one of three large volcanoes that occur on the Elysium Rise-- the others are Hecates Tholus (northeast of Elysium Mons) and Albor Tholus (southeast of Elysium Mons). The volcano rises about 12.5 kilometers (7.8 miles) above the surrounding plain, or about 16 kilometes (9.9 miles) above the martian datum-- the "zero" elevation defined by average martian atmospheric pressure and the planet's radius.

Elysium Mons was discovered by Mariner 9 in 1972. It differs in a number of ways from the familiar Olympus Mons and other large volcanoes in the Tharsis region. In particular, there are no obvious lava flows visible on the volcano's flanks. The lack of lava flows was apparent from the Mariner 9 images, but the new MOC high resolution image--obtained at 5.24 meters (17.2 feet) per pixel--illustrates that this is true even when viewed at higher spatial resolution.

Elysium Mons has many craters on its surface. Some of these probably formed by meteor impact, but many show no ejecta pattern characteristic of meteor impact. Some of the craters are aligned in linear patterns that are radial to the summit caldera--these most likely formed by collapse as lava was withdrawn from beneath the surface, rather than by meteor impact. Other craters may have formed by explosive volcanism. Evidence for explosive volcanism on Mars has been very difficult to identify from previous Mars spacecraft images. This and other MOC data are being examined closely to better understand the nature and origin of volcanic features on Mars.

The three MOC images, 40301 (red wide angle), 40302 (blue wide angle), and 40303 (high resolution, narrow angle) were obtained on Mars Global Surveyor's 403rd orbit around the planet around 9:58 - 10:05 p.m. PDT on July 2, 1998. The images were received and processed at Malin Space Science Systems (MSSS) around 4:00 p.m. PDT on July 4, 1998.

Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO.

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