It’s been a busy couple of weeks on and around Mars and with space exploration in general. This being the case, I’m going to be tagging some of the other items of potential interest to the end of this Curiosity update.
On September 24th, Curiosity obtained its first sample of rock gathered from the foothills of “Mount Sharp”, or Aeolis Mons as it is more correctly named. The sample was taken from a rock in the area dubbed “Pahrump Hills”, an uprising within the initial transitional zone between what is regarded as the floor of Gale Crater and the material making up the huge mound of “Mount Sharp” located at the centre of the crater.
The rover officially arrived within the area of interest on September 19th, and conducted surveys of its surroundings and a potential candidate area was selected for sample gathering. On September 22nd, an initial “mini drill” test operation was carried out on a rock surface in the target area, dubbed “Confidence Hills”, to assess its suitability for sample gathering.
As noted in a previous update, “mini drilling” operations are used to test a potential target for a range of factors prior to actually committing the rover’s drill to a sample-gathering exercise, the intention being to ensure as far as possible that nothing untoward may happen which may damage the drill mechanism or adversely impact future sample gathering work.
The September 22nd mini drilling was important for two reasons; not only was it intended to assess the suitability of the target rock for sample gathering, it also marked the first time the drill cut into what is essentially “new” and “softer” material compared to previous drilling activities, and it was doubly unclear as to how the drill or the rock might react.
The sample-gathering drilling took place on September 24th, PDT (Sol 759 for Curiosity on Mars) and resulted in cutting a hole some 6 centimetres (2.6 inches) deep into the target rock and the successful gathering of tailings. “This drilling target is at the lowest part of the base layer of the mountain, and from here we plan to examine the higher, younger layers exposed in the nearby hills,” said Curiosity Deputy Project Scientist Ashwin Vasavada following the operation. “This first look at rocks we believe to underlie Mount Sharp is exciting because it will begin to form a picture of the environment at the time the mountain formed, and what led to its growth.”
Curiosity is liable to stay within the “Pahrump Hills” area for a while prior to moving up onto the Murray Formation above it, which is regarded as the formal boundary area between “Mount Sharp” and the crater floor, and as such is designated a target of particular interest. As a part of its studies of “Pahrump Hills”, and as well as gathering an initial rock sample, the rover has been surveying the rocks in its immediate surroundings with other instruments including the ChemCam laser system and the high-magnification Mars Hand Lens Imager camera, also mounted on the robot arm.
Of particular interest to the science team have been a series geometrically distinctive features on the rock surface. These are thought to be common to the Murray formation mudstones, and are believed to be the accumulations of erosion-resistant materials. They occur both as discrete clusters and as dendrites with formations arranged in tree-like branching. By investigating the shapes and chemical ingredients in these features, the team hopes to gain information about the possible composition of fluids at this Martian location long ago.
Currently, the sample gathered from the “Confidence Hills” are held within CHIMRA, the Collection and Handling for In-Situ Martian Rock Analysis system, in the rover’s robot arm. This is a mechanism that allows sample material to be graded by the size of the tailings by passing them through a series of sieves as the robot arm is vibrated at high rates, producing multiple samples which can then be delivered in turn to the rover’s onboard science instruments for detailed analysis.