On Sol 279 of its mission (May 19th 2013), Curiosity completely its second major drilling operation intended to retrieve cuttings from inside a rocky surface in the “Yellowknife Bay” area of Gale Crater on Mars.
The operation took place on a rocky outcrop dubbed “Cumberland” a short distance from the site of the initial drilling operation, which took place on a rocky area dubbed “John Klein” in February 2013. Samples gathered from the drilling will be processed by CHIMRA – the Collection and Handling for In-situ Martian Rock Analysis – prior to being delivered to the Chemistry and Minerology (CheMin) and Sample Analysis at Mars (SAM) instrument suites inside the body of the rover.
The primary aim of this work is to check findings gathered in the analysis of samples obtained from “John Klein”. These indicate that Yellowknife Bay long ago had environmental conditions favourable for microbial life, with conditions which included the key elemental ingredients for life, an energy gradient that could be exploited by microbes, and water that was not harshly acidic or briny.
“Cumberland” itself is very similar to “John Klein”, but has more of the erosion-resistant granules that cause the surface bumps. The bumps are concretions, or clumps of minerals, which formed when water-soaked the rock long ago. Analysis of a sample containing more material from these concretions could provide information about the variability within the rock layer that includes both “John Klein” and “Cumberland”.
The initial hole cut into “Cumberland”, which lies some 2.75 metres (9 feet) from “John Klein”, was made to a depth of 6.6 cm (2.6 inches), which was sufficient to force cuttings up into the collection bowl in the drill head itself. In the coming days the cuttings will be passed into CHIMRA and then to the rover’s sample-gathering scoop where they’ll be visually checked by the rover’s camera systems prior to being passed through the sieving mechanisms within CHIMRA ready for delivery to CheMin and SAM.
Once delivered to both instruments, analysis of the samples is liable to take a place over a few days prior to results being returned to Earth.