Imagine a field geologist hiking a dusty landscape. She spies a ridge of rock, climbs to it, whacks off a protruding bit with a hammer. She stoops to pick up the broken piece, turning its freshly fractured face upward. From its color and crystals, she deduces its composition. She drops the rock and makes a note in her field notebook. Then she walks on.

On Earth, this whole process takes only minutes. On Mars, where robots substitute for human geologists, the same operation takes a day, sometimes several. Mars scientists eagerly anticipate a time when we’ll see human geologists walking on Mars, using their brains and hands to rapidly increase the rate at which we learn about Mars’s past.…  Seguir leyendo »