We made good progress through Gediz Vallis in the weekend drive, landing in a segment of the channel containing a mix of loose rubble and other channel-filling debris. Amongst the jumbled scene, though, particular objects of interest caught our eye: bright rocks. In past workspaces in Gediz Vallis, similar bright rocks have been associated with very high to almost pure sulfur contents. As all good geologists know, however, color is not diagnostic, so we cannot assume these are the same as sulfur-rich rocks we have encountered previously. The only way to know is to collect data, and that was a significant focus of today’s plan.