They were pretty happy out at JPL today after scientists guided the Phoenix lander to a spot near the north pole of Mars, just one degree of tilt off perfect horizontal. Then the photos started coming back. Kenneth Chang in the New York Times writes: "The next few days will be spent checking out the condition of the spacecraft. Then it will begin the first up-close investigation of Mars’s northern polar region. That area became a prime subject of interest for planetary scientists after NASA’s orbiting Odyssey spacecraft discovered in 2002 vast quantities of water ice lying a few inches beneath the surface in the polar regions."

Mars’s surface is currently far too cold for life to exist, but in the past, the planet’s axis might have periodically tipped over so that its north pole pointed at the sun during summer. That could have warmed the ice into liquid water.

With liquid water comes the possibility of life.

Susan Kitchens at 2020 Hindsight pronounces the landing "Perfect. Amazing."

NYT, LAT, Arizona Republic, Planetary Society live-blog, Wired Science live-blog

NASA Jet Propulsion Laboratory press release and mission home.

Pool photo by Lawrence K. Ho via NYT