Phoenix: A life

phoenix3.jpg.jpg Phoenix has been incommunicado since the end of October, the Mars mission ending just before a shell of carbon dioxide ice would entomb the three-legged lander. But the legacy of this little lander that sort of could keeps on living. A suite of papers published today in Science rounds up the lander’s greatest hits, all of which had been published as the mission went along. In summary:


* Phoenix found subsurface ice. In some ways, this was patently obvious from the moment pictures revealed white stuff exposed by the lander’s retrorockets. Mars has permanent polar caps, and Odyssey had found strong evidence that these caps extend into the subsurface to areas that Phoenix explored. But the team was still thrilled to see H20 in a mass spectrometer after struggling to get bits of ice into an oven. In the first of the Science papers, principal investigator Peter Smith, of the University of Arizona, concludes further that the ice melted in the geologically recent past. The poles of Mars may thus have been habitable.

* Phoenix found calcium carbonate, a mineral that forms in the presence of water, and important evidence for the habitability argument.

* Phoenix found an intriguing mineral component called perchlorate, both a key ingredient in rocket fuel, and a salt that can drastically lower the freezing point of water. It led to great debate over whether strange lumps on the lander’s legs were nuggets of ice or droplets of water.

* Phoenix saw water-ice clouds: It, in fact, snows on Mars.

This was the science. But Phoenix was notable for a lot of other reasons. After several failed attempts, it was the first mission to the polar regions — a seemingly obvious place to go in looking for evidence for life, but also very difficult terrain in which to land, and difficult conditions in which to survive, especially if you’re dependent on the Sun for power.

Phoenix was also the first powered landing since Viking, and an important chance for engineers to redeem reverse-thrusting methods that may be important in future mission. And it was the first mission in NASA’s Scout mission line, a small, relatively inexpensive line of missions that may now be ending. Phoenix proved that you could get to the surface of Mars for about a half billion dollars. The Mars Science Laboratory will cost more than four times as much.

But the most interesting non-scientific aspect to Phoenix was its anthropic qualities. Thousands followed the mission’s personified Twitter messages through the martian polar summer. In our feature story take on the mission, we presented the mission as a race, as scientists scrambled to get the data they needed before the sinking sun stopped delivering enough power to solar panels. But Phoenix was as much a delicate and precarious life as it was a race. Unlike other missions, the knowledge of its mortality was with the team members from the start. Sure, everyone is pleased with the indefatigable and seemingly immortal rovers Spirit and Opportunity. But the arc of Phoenix was altogether more poignant. Here’s a slideshow of some of its top moments.

Leave a Reply

Your email address will not be published. Required fields are marked *