Sols 3919-3920: A ‘Blissful’ Martian Rock Paradise, Straight Ahead!

Earth planning day: Monday, August 14, 2023

The Gediz Vallis Ridge represents a hugely interesting and enigmatic feature, one that we have been talking about since landing (and probably well before that), but one that seemed so very very far away. We have been discussing science goals and campaigns for when we reach it at our bi-annual long term planning meetings …. and every chance in between. But it has always felt so far away - until now! Over the past 11 years, Curiosity has traveled 30+ km (see the interactive map here), and the ridge is close.

Since leaving the “Jau” crater cluster, we have been driving to an area at the base of the ridge which appears to mark a contact between the underlying “sulfate unit” bedrock and the overlying ridge. You can see it in the accompanying image, with lighter coloured rocks in the lower half of the image (the sulfate unit) and the darker rocks in the upper half (the Gediz Vallis ridge). We are hoping to get close enough to do contact science on some of the darker boulders and rocks scattered across the ridge unit, which we surmise are from the ridge itself. This stop will also provide excellent viewsheds for imaging further up the ridge. We are so close, we can almost taste it. In fact, one of our geologists decided they could almost smell the ridge from today’s workspace – it smells like geological “bliss” in case you are wondering!

Sadly, due to some unstable wheel placement, it was decided to keep the arm stowed in today's plan, rather than risk taking it out. But that’s okay – we are within a couple of drives of hitting that Gediz Vallis Jackpot, we can wait a couple of more sols! In the meantime, we crammed the plan with ChemCam activities, lots of imaging and ENV activities.

Mastcam will take further images of the current workspace and the “nearfield” (just beyond the reachable workspace), looking at the bedrock and the dark float stones scattered across it. The 5x1 “Metsovo” mosaic focuses on layering within the bedrock. Mastcam will look at two of the float rocks in more detail, taking a multispectral image of “Psychro Cave” and documentation images of “Syros,” which will be today’s ChemCam LIBS target. In addition, ChemCam planned an RMI (long distance image) on “Foinikas,” a larger boulder on the ridge, with a really interesting texture, and an AEGIS image of the post-drive workspace. Of course, we are also imaging the Gediz Vallis ridge. A 14x1 mosaic will look at the diversity of the rock types strewn on the ridge unit.

ENV planned several activities too. Mastcam will take a pair of tau images, to help constrain the levels of dust in the atmosphere. There are several Navcam movies planned (a cloud shadow movie, zenith movie, two suprahorizon movies) and a large dust devil survey.

Our drive will take us about 24 metres, getting us closer and closer to those Gediz Vallis ridge rocks …. I can almost smell that geological bliss myself now!

Written by Catherine O'Connell-Cooper, Planetary Geologist at University of New Brunswick