Abstract

The Curiosity rover has now been on Mars for just over 600 Martian days. One of the mission’s key discoveries is a lacustrine mudstone with all the attributes thought to be required for habitability. We (the MSL science team) obtained a radiometric age and a surface exposure age on thus mudstone - the first ever obtained on another planet - with remarkable results. Looking forward, I have also been involved in the development of a new geochronology method - double isotope dilution K-Ar dating - which has documented potential to obtain high precision/high accuracy (few percent uncertainty) ages on planetary surface rocks, yet meets the exacting requirements for spaceflight. An instrument to implement this method has been proposed for the Mars 2020 mission, a Curiosity-class rover being considered for launch in 2020 and designed to seek the signs of ancient life. A key additional goal of the proposed Mars 2020 mission is progress towards return of samples to Earth. As project scientist for this new mission, I am now deeply engaged with engineers designing and implementing this rover; this has been a fascinating departure from my work in terrestrial geochemistry.