In the Land of the Meridian: fieldwork in Mars

摘要

As I begin to write, in July 2004, a robot geologist called Opportunity is perched on a 25° slope on the inside of a 180m diameter impact crater on Mars. For the past few weeks it has been slowly edging its way down into the crater, examining exposed rock strata on the way. The team of engineers and scientists on Earth who are responsible for planning the robot's explorations have named the crater Endurance, after the ship that took Sir Ernest Shackleton's expedition to the Antarctic in 1914. There is a distinct possibility that, like Shackleton's ship (which became trapped in pack-ice), the robot will not be able to extract itself from this furthest point in her six-month exploration, so it is proceeding with extreme caution. The risk is justified, however, for Opportunity is achieving something that no previous planetary explorer, human or robot, has managed: geological field mapping and lithostratigraphical logging of exposed in situ bedrock on another planet.