It will be a long time until humans put boots on Mars--at least until the 2030s and possibly a lot longer, depending on what the incoming Trump administration thinks about NASA's unfunded exploration plans. But through our robotic emissaries, we have already made quite a mark on the planet. The newest one, on October 19, was the sad and unexpected splat from the European Space Agency's Schiaparelli probe. Apparently, betrayed by an errant altitude reading from one of its instruments, the lan
