The Mars Science Laboratory (MSL) began its journey to Mars in November, 2011, and arrived nine months later in Gale crater. Mt. Sharp is three times higher than the Grand Canyon is deep and lies at the centre of Gale crater. MSL carries ten instruments on the Curiosity rover, including CheMin, a miniature X-ray diffraction (XRD) and fluorescence (XRF) instrument.
Back on Earth XRD is a well-established technique and can provide more accurate identifications of minerals than any method previously used on the Red Planet. The first XRD data were successfully measured on Mars in October, 2012, coinciding with the 100th anniversary year of the discovery of XRD by von Laue.
The CheMin instrument first analysed a sample of martian soil/dust from a dune and found that it is very similar to soils on the flanks of Mauna Kea volcano in Hawaii, containing minerals commonly found in basalts, along with amorphous or glassy material.
Clay minerals are consistent with formation in water, and the age of these rocks shows that Mars hosted wet environments more recently than previously thought. In addition, the particular minerals found in the drilled rocks are compatible with an environment that was potentially habitable to life, with near-neutral pH and moderate temperatures.
This is the subject of a public lecture being presented by David Bish PhD, who is a co-investigator on the CheMin instrument which is on the Curiosity rover, currently operating on the martian surface.