The Phoenix Mars Mission, which launched last August, completed its roughly 423-million-mile journey on Sunday night, with a successful landing on Mars’s polar cap. After a smooth landing, the 18-foot-long lander has relayed back 100-some images of its surroundings, as well as of itself and its shadow.
There have been many spacecraft sent to Mars, but most have failed; the last attempt to land on a Martian polar cap failed in 1999, when Mars Polar Lander lost communication as it descended to the planet.
Phoenix will look for signs of past habitability by trying to characterize the history of water on Mars and by looking for biological components in the soil. The spacecraft, powered by solar arrays, will use a nearly eight-foot-long arm to dig about a foot and a half beneath the surface, where scientists expect (based on data from the Mars Odyssey orbiter) vast sheets of ice to lie. An impressive array of cameras, sensors, and microscopes will monitor the environment and analyze the icy soil samples. Phoenix has roughly three months to complete its mission, before Martian winter sets in, freezing the spacecraft in solid carbon dioxide.