The MRO periodically checks in on Curiosity with its ultra-powerful High-Resolution Imaging Science Experiment (HiRISE) camera when the satellite orbits overhead. This Mars robot "buddy system" has also been done for NASA's veteran Opportunity rover and, in both cases, the orbital perspective has helped mission controllers identify points of scientific interest "over the horizon."
It's also a reassuring perspective, allowing rover drivers to plan the safest driving routes.
But as this HiRISE observation shows, there's an interesting lack of rover tracks that have been clearly visible during previous orbital passes by the MRO. Curiosity's last orbital portrait was snapped over 4 months ago.
"Unlike other regions of for which Curiosity has traversed, here the rover tracks are not apparent, likely because the disturbed, underlying, dark sand is similar in tone to that on the surface," writes Nathan Bridges, HiRISE Investigation Scientist at NASA's Jet Propulsion Laboratory in Pasadena, Calif.
Imaged on April 8, Curiosity can be seen working at the "Pahrump Hills" location at the base of Aeolis Mons (known as Mount Sharp, a 5.5 kilometer-high mountain in the center of Gale Crater). The region has proven itself to be a goldmine of geological features, rich in sandstone, siltstone and calcium sulfate veins, revealing Mars' ancient wet past.
Apart from the dark sand being a similar color to the bedrock, there's also the possibility that the Martian wind may have erased Curiosity's tracks, something mission scientists will be keen to understand as these high-resolution images can track the motion of sand around the rover's place of continuing work.
See video below for more images of Mars from HiRise
(Source: High Rise Imaging Science Experiment)