NASA's Mars rover Curiosity held its
Mars Hand Lens Imager (MAHLI) camera about 10.5 inches (27 centimeters) away
from the top of a rock called "Bathurst Inlet" for a set of eight
images combined into this merged-focus view of the rock. This context image
covers an area roughly 6.5 inches by 5 inches (16 centimeters by 12
centimeters). Resolution is about 105 microns per pixel.
MAHLI took the component images for this
merged-focus view, plus closer-up images of Bathurst Inlet, during Curiosity's
54th Martian day, or sol (Sept. 30, 2012). The instrument's principal
investigator had invited Curiosity's science team to "MAHLI it up!"
in the selection of Sol 54 targets for inspection with MAHLI and with the other
instrument at the end of Curiosity's arm, the Alpha Particle X-Ray
Spectrometer.
The Bathurst Inlet rock is dark gray and
appears to be so fine-grained that MAHLI cannot resolve grains or crystals in
it. This means that the grains or crystals, if there are any at all, are
smaller than about 80 microns in size. Some windblown sand-sized grains or dust
aggregates have accumulated on the surface of the rock but this surface is
clean compared to, for example, the pebbly substrate below the rock (upper left
and lower right in this context image).
MAHLI can do focus merging onboard. The
full-frame versions of the eight separate images that were combined into this view
were not even returned to Earth -- just the thumbnail versions. Merging the
images onboard reduces the volume of data that needs to be downlinked to Earth.
Image credit: NASA/JPL-Caltech/Malin
Space Science Systems
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