Monday, May 26, 2008
Photos credit: NASA/JPL-Calech/University of Arizona
I'm happy to say that the Mars Phoenix Lander has landed safely on Mars. The spacecraft was launched from Cape Canaveral last August, and successfully set down in the part of Mars known as the Vastitas Borealis (literally, northern vastness or widespread lowlands). The Vastitas Borealis lies 3-4 km below the mean radius of the planet (the Martian equivalent of sea level), that completely encircles the northern hemisphere of Mars from about 50°-60° North to about 80° North, where it meets the Planum Boreum, the northern polar plain where the ice cap is located. It is believed that the Vastitas Borealis may have been an ocean in Mars' ancient past, and that the Phoenix Lander may discover ice beneath a thin layer of dirt.
Unlike the rovers Spirit and Opportunity, which are both mobile and have been operational for a number of years, the Phoenix Lander will remain in one place, where it landed, and is expected to survive for about three months or so, when the weather will freeze the spacecraft. In the meantime, the Phoenix Lander has an arm that will scoop soil and ice samples and place them into several chemistry laboratories inside the spacecraft, which will try to determine the soil chemistry, the amount of water and water vapor in the soil, and the soil's level of conductivity. The goal is to determine whether the Martian environment has ever been favorable to microbial life. In addition to the above-mentioned equipment, there's also several cameras on board plus a meteorological station, all of which are standard equipment for Martian vehicles today.
The two photos here are some of the first images taken by the Phoenix Lander. Both photos, which are approximate-color images, show a landscape that is strewn with tiny pebbles and shows polygonal cracking, a pattern seen widely in Martian high latitudes and also observed in permafrost terrains on Earth. The polygonal cracking is believed to have resulted from seasonal freezing and thawing of surface ice.