Using its weather station, Phoenix sent back daily weather reports, and with its LIDAR (a laser-based version of radar) it recorded the first snow ever detected falling on another planet.
It survived dust storms and whirlwinds, and while some of its instruments didn't exactly work perfectly the first time, as in the case when soil from Phoenix's scoop refused to neatly fall into its ovens, the mere fact that the soil was "clumpy" has told scientists much about the soil they would never have learned otherwise.
Sure, it didn't get up and climb to the top of a hill, but Phoenix has done exactly what it was designed to do, and done it almost perfectly.
Spirit and Opportunity would not have lasted more than a few months if they'd been sent to where Phoenix landed, as their greater solar power needs could not have been met at such an inhospitable landing site. They too would not have survived the winter at 68 degrees North.
Built with components initially designed for the failed Mars Polar Lander mission and the cancelled Mars Surveyor Lander (along with new instruments from Canada, France, the U.S., Denmark and the U.K.), Phoenix is a shining example of international cooperation on a space mission, built on a shoe-string budget.
NASA's next Mars rover to be launched in 2011, the Mars Science Laboratory, has a budget more than five times greater than that of Phoenix.
Phoenix finally stopped communicating with Earth on 10 November 2008, two weeks earlier than its controllers had hoped, but by then it was well into extended mission time. Its 90-day primary mission had been successfully completed in late August, anything after that was a bonus.
It appears to have been finally silenced by a dust storm, the dust falling on the solar panels proved to be too much, and its power fell to below the critical limit needed to keep it alive and communicating.
To the south, much closer to the equator, the same dust storm has caused Spirit to be put into "conservation" mode, only doing limited observing, and communicating with Earth only when absolutely necessary.
Was the mission a success? Most definitely yes. Nothing has previously ventured as far North on Mars, and nothing has previously been able to so decisively prove the presence of water on Mars and the habitability of the Northern Plains.
This is one mission that will be long remembered by all those who look up at Mars in the night sky. Phoenix is the mission that has seen our hopes of eventually sending humans to Mars reborn anew from the ashes of the phrase "it's never going to happen."
Marion Anderson is an expert in the mineralogy and geomorphology of Mars, based at Monash University in Melbourne, Australia.

