Curiosity is working with material from the fourth scoop of soil it collected at the "Rocknest" patch of dust and sand. On Sol 77, a sieved portion from this scoop was delivered to the Chemistry and Mineralogy (CheMin) instrument inside the rover. This is the second soil sample for CheMin analysis. The material from the fourth scoop is also being used to scrub internal surfaces of the rover's sample-processing mechanisms in preparation for delivery of a sample from a later scoop to the Sample Analysis at Mars (SAM) instrument.
Sol 78 activities included analysis of an atmosphere sample by SAM's Quadrupole Mass Spectrometer and monitoring of environmental conditions by the Rover Environmental Monitoring Station (REMS) and the Radiation Assessment Detector (RAD).
Sol 78, in Mars local mean solar time at Gale Crater, ended at 10:57 a.m. Oct. 25, PDT (1:57 p.m., EDT).