Curiosity is investigating the different surface expressions of the Greenheugh pediment, and the weekend drive put the rover right next to some “gator-back terrain” – some evenly spaced ridges with a blocky expression, as seen in the above Navcam image. Today’s one sol plan is focused on a close encounter with one of these ridges through contact science and remote sensing.
The plans starts with a ChemCam LIBS observation of “Scandal Beck” to assess the chemistry of the blocky outcrop. Then we’ll acquire 2 long-distance RMI mosaics to investigate the stratigraphy exposed in Gediz Vallis ridge. Afterwards, Mastcam will take two large mosaics to look at the sedimentary structures exposed in the “gator-back” ridge and characterize the erosion of these blocks.
The rover will also take a Navcam dust devil survey now that we’ve entered the dusty season on Mars. In the afternoon, MAHLI will take a closer look at the grain size of these rocks at the target “Calder,” followed by an overnight APXS integration to learn about its chemistry. Early the next morning Mastcam will acquire a mosaic of Gediz Vallis ridge to document this feature from our good vantage point and morning lighting conditions.
Prior to arriving on the Greenheugh pediment, the team had been intrigued by the “washboard texture” preserved on its surface, as identified in orbital images. Now that we’re here it’s quite surprising to see how rugged it is, and the informal description of this “gator-back terrain” seems very fitting!
Sols 3419-3420: Assessing the “Gator-Back Terrain”
by Mark Salvatore | Planetary Geologist at University of Michigan
After a ~15 meter drive to the west along the top of the Greenheugh Pediment, Curiosity is now positioned at an interesting textural transition within the pediment’s surface units. Quite a large amount of the pediment is dominated by a washboard-like pattern at the surface that can be easily observed from orbit, while the region Curiosity ascended onto the pediment surface is rugged yet lacks those clear washboard-like features. With this latest drive, Curiosity is now positioned at the transition between these two surface units, and the team is continuing to assess the traversability of this units.
With this new vantage point, the plan is for Curiosity to spend the weekend characterizing the different morphological features observed on top of the pediment. The weekend plan will start with several Mastcam imaging sequences designed to characterize the washboarding that is observed in the landscape ahead of the rover. The terrain’s small-scale roughness and oriented ventifacted rocks led the Science Team to informally refer to these textures as “gator-back terrain” (see image).
Curiosity will also perform two ChemCam LIBS analyses on two different targets – a smooth outcrop target named “Macmerry” and a rougher knobby target named “Ochiltree.” After a ChemCam passive sky observation around midday on sol 3419, Curiosity will unstow her arm to conduct an APXS integration on the outcrop target named “Blackadder” and an overnight APXS measurement to characterize the martian atmosphere.
Finally, on the sol 3420, Curiosity will complete her Mastcam and ChemCam observations (including a long-distance remote imaging mosaic) before embarking on a planned ~35 meter drive to the west to continue the investigation of the pediment and the interesting surface textures found on its surface.
Related Links
Curiosity Mars Science Laboratory
Mars News and Information at MarsDaily.com
Lunar Dreams and more