Mars Orbiter sends colour snap of Red Planet
Tasty HiRISE test image
The Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment (HiRISE) camera has captured its first colour image* of the Red Planet, snapped as part of a series of test images to calibrate the camera:
The image - a composite of green, red, and near-infrared - shows a "story of geologic change in the eastern Bosporos Planum region", according to the HiRISE team blurb, in which "wind and sublimation of water or carbon dioxide ice have partially eroded patches of the smooth-textured deposits, leaving behind areas of layered and hummocky terrain".
The NASA vehicle arrived at Mars on 10 March and now faces a six-month period of "aerobraking" (repeatedly descending into the atmosphere and using the resulting drag to slow down) in order to attain its final orbit of between 255 and 320 kilometres above the Martian surface. The above pic was grabbed from an altitude of 1500km during a 10 minute window of opportunity currently available to mission controllers during the orbiter's elongated 35 hour orbit.
During these 10 minute drive-bys, New Scientist reports, the Sun had hardly broken the Martian horizon. Accordingly, colour images were difficult to obtain, but "this first image nevertheless shows some very interesting and informative colour variations", noted HiRISE top boffin Alfred McEwen of the University of Arizona.
Specifically, the blue tinge on the left-hand side of the picture may show early-morning fog, while streaks on the right seem to be where wind action has exposed an underlying stratum of darker soil. ®
*We have rotated the NASA original 90 degrees CW.
Here's further HiRISE team background on the above image:
Image AEB_000001_0000 was taken by HiRISE on 24 March, 2006. The image is centered at 33.65 degrees south latitude, 305.07 degrees east longitude. It is oriented such that north is 7 degrees to the left of up. The range to the target was 2,493 kilometers (1,549 miles). At this distance the image scale is 2.49 meters (8.17 feet) per pixel, so objects as small as 7.5 meters (24.6 feet) are resolved. In total this image is 49.92 kilometers (31.02 miles) or 20,081 pixels wide and 23.66 kilometers (14.70 miles) or 9,523 pixels long. The image was taken at a local Mars time of 07:33 and the scene is illuminated from the upper right with a solar incidence angle of 78 degrees, thus the sun was 12 degrees above the horizon. At an Ls of 29 degrees (with Ls an indicator of Mars' position in its orbit around the sun), the season on Mars is southern autumn.