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Color image of Olympus Mons - Sections of MOC images P024_01 and P024_02, shown here in color composite form, were acquired with the low resolution red and blue wide angle cameras over a 5 minute period starting when Mars Global Surveyor was at its closest point to the planet at the beginning of its 24th orbit (around 4:00 AM PDT on October 20, 1997). To make this image, a third component (green) was synthesized from the red and blue images. During the imaging period, the camera was pointed straight down towards the martian surface, 176 km (109 miles) below the spacecraft. During the time it took to acquire the image, the spacecraft rose to an altitude of 310 km (193 miles). Owing to data camera scanning rate and data volume constraints, the image was acquired at a resolution of roughly 1 km (0.609 mile) per pixel. The image shown here covers an area from 12 degrees to 26 degrees N latitude and 126 degrees to 138 degrees W longitude. The image is oriented with north to the top.
Olympus Mons is the largest of the major Tharsis
volcanoes, rising 25 km (15.5 miles) and stretching over nearly 550 km (340 miles)
east-west. The summit caldera, a composite of as many as seven roughly circular collapse
depressions, is 66 by 83 km (41 by 52 miles) across. Also seen in this image are water-ice
clouds that accumulate around and above the volcano during the late afternoon (at the time
the image was acquired, the summit was at 5:30 PM local solar time).
Color image of Valles Marineris - MOC images P013_01 and P013_02 were acquired with the low resolution red and blue wide angle cameras at 2:14 PM PDT on October 3, 1997, about 11 minutes after Mars Global Surveyor passed close to the planet for the thirteenth time. To make a color image, a third component (green) was synthesized from the red and blue images. During the imaging period, the spacecraft was canted towards the sun-lit hemisphere by 25 degrees, and the MOC was obliquely viewing features from about 600 to 1000 km (360 to 600 miles) away. The resolution at those distances was between 350 and 600 meters (0.25 to 0.37 miles) per picture element. The image covers an area from 73 degrees to 86 degrees W longitude and 5 degrees N to to 10 degrees S).
In the image above, north is to the top. The camera is viewing towards the west. The image
is the composite of MOC frames P013_01 and P013_02. Because the MOC acquires its
images one line at a time, the cant angle towards the sun-lit portion of the planet, the
spacecraft orbital velocity, and the spacecraft rotational velocity combine to distort the image
slightly. However, the wide angle cameras provide a fairly realistic portrayal of what one
would see looking out across Mars from the Orbiter. Notable in this image are the late
afternoon clouds and hazes that are concentrated within the Valles Marineris canyon system.
Labyrinthus Noctis - This is MOC frame P005_03, a subset of PIA00941. MOC image P005_03 was acquired at 6:25 AM PDT on September 19, 1997, about 11 minutes after Mars Global Surveyor passed close to the planet for the fifth time. During the imaging period, the spacecraft was canted towards the sunlit hemisphere by 25 degrees, and the MOC was obliquely viewing features about 1600 km (1000 miles) away. The resolution at that distance was about 6 meters (20 feet) per picture element (pixels), but in order to improve the number of gray levels, the pixels were summed in both the cross-track and along-track directions, yielding final resolution of about 12 meters (40 feet) per pixel. The MOC image covers an area about 12 km X 12 km (7.5 X 7.5 miles).
Labyrinthus Noctis is near the crest of a large (many thousands of kilometers) updoming of
the Martian crust, and the 2000 meter (6500 foot) deep canyons visible in these pictures are
bounded by faults. Debris shed from the steep slopes has moved down into after the
canyons opened. Small dunes are seen in the lowest area, beneath the high cliffs.
Area south of Schiaparelli - This view of Mars, showing a small area immediately south of the large crater Schiaparelli, was taken by the Mars Orbiter Camera during its 23rd pass close to the planet. It was acquired on October 18, 1997, at 3:42 PM PST, about 10 minutes after closest approach. The image covers an area 4.6 km (2.9 miles) wide by 21.1 km (13.1 miles) high, at a resolution of 4.5 m by 7.9 m (14.75 X 25.9 feet) per picture element, and is centered at 5.5 degrees S, 340.7 degrees W. The local time of the acquisition was about 4:50 PM.
The image at left shows the location in the best available image from the Viking Orbiters
(approximately 240 m/pixel). The center image is the full image, while at right is an enlarged
portion of it. The two right images are available at higher resolution as PIA01025 and
Ganges Chasma -
On October 26, 1997, MOC took this image of Mars 10 minutes after its closest approach to
the planet (1:46 AM PST). The view shows the floor of western Ganges Chasma (7.8 degrees S
51.8 degrees W), covering an area 2.6 km (1.6 miles) wide by 45.4 km (28.2 miles) long at a
resolution of 5 by 7.4 meters (16.4 by 24.3 feet) per picture element. The local time on Mars
when the picture was taken was 4:35 PM.
The center image (available at higher resolution as PIA01028) shows the northern portion of
the area inscribed in the left image. The right image (PIA01029) shows the southern portion.
Layered features in Valles Marineris - Most remarkable about this MOC image is the discovery of light and dark layers in the rock outcrops of the canyon walls. In the notable, triangular mountain face (at center), some 80 layers, typically alternating in brightness and varying in thickness from 5 to 50 meters (16 to 160 feet), are clearly visible. This shear mountain cliff, over 1000 m (3200 ft) tall, is only one of several outcrops that, together, indicate layering almost the entire depth of the canyon.
This type of bedrock layering has never been seen before in Valles Marineris. It calls into
question common views about the upper crust of Mars, for example, that there is a deep
layer of rubble underlying most of the martian surface, and argues for a much more complex
early history for the planet.
NSSDC Image Catalog images of Mars
- More Mars Global Surveyor pictures
NSSDC Photogallery - more images of Mars
Mars Global Surveyor home page at NSSDC