Curiosity Chemistry & Camera Remote Micro-Imager (RMI) telescope photo taken on Sol 2893, September 25, 2020.
Credit: NASA/JPL-Caltech/LANL

NASA’s Curiosity Mars rover is now performing Sol 2897 tasks.

Nearly a month ago the rover team started taking Remote Micro-Imager (RMI) telescope images to study the stratigraphy of some sedimentary benches over 300 – 650 feet (100-200 meters) distant from the robot’s current location.

Reports Roger Wiens, a geochemist at Los Alamos National Laboratory in New Mexico: The pointing was a little high on the first set of images and the rover’s Chemistry and Camera (ChemCam) telescope, which is programmed to focus automatically on whatever is at the center of the image, ended up focusing on the marker bed in the background several kilometers away.

Chemistry & Camera (ChemCam) Remote Micro-Imager (RMI) telescope photos acquired on Sol 2894 September 26, 2020
Credit: NASA/JPL-Caltech/LANL

Data for interpretation

“We eventually got the appropriate images of the benches, but in the meantime, the team decided to take more images of the marker bed,” Wiens explains.

“Curiosity is not expected to explore the region around the marker bed for another couple of years, and so in the meantime, these images will provide interesting data for interpretation.”

Curiosity’s Chemistry and Camera tool is known as ChemCam – a laser, camera and spectrograph work together to identify the chemical and mineral composition of rocks and soils.
Credit: NASA/JPL-Caltech

Rock strata

What is a “marker bed?”

It is an important concept in sedimentary geology, Wiens notes. “It is a bed of rock strata that are easily distinguished and are traceable over a long horizontal distance. A marker bed is very useful in determining the chronological order of geological events and correlating them from one location to another.”

Wiens adds that rock strata that lie above the marker bed in one location are assumed to have been deposited later than rock strata that are seen below the marker bed, even if the two sets of strata are many kilometers distant from each other, as long as the marker bed is seen in both locations.

Curiosity Right B Navigation Camera image acquired on Sol 2895, September 27, 2020.
Credit: NASA/JPL-Caltech

Chronology of strata

“One particular bed on the lower part of Mt. Sharp is visible in orbital images over a significant fraction of the circumference of the mountain,” Wiens points out. “It had been noted in the scientific literature already several years ago.”

In due course, Wiens reports, this marker bed could be used to tie the chronology of strata observed up close by the Curiosity rover to other parts of Gale Crater, for example, regions many kilometers to the south along the slopes of Mt. Sharp.


Leave a Reply