For all the times robot probes have orbited or landed on Mars, none had ever visited its polar region — where the greatest concentrations of ice and water (and arguably the most evidence of life) are to be found. That changed in May when NASA's Phoenix lander touched down in Mars's far north and began scraping, sampling and sniffing its surroundings. Phoenix found nothing that yet changes the picture of Mars as a dead world, but it reinforced the planet's image as a once-wet place that could have teemed with organisms. The ship was not expected to survive the punishing climate for long and in November, the encroaching darkness and cold of the Martian winter silenced it for good.