Adirondack (Mars)  Adirondack is the nickname for Mars Exploration Rover "Spirit"'s first target rock. Scientists chose Adirondack to be "Spirit"s first target rock after considering another, called Sashimi, that would have been a shorter, straight-ahead drive. "Spirit" traversed the sandy martian terrain at Gusev Crater to arrive in front of this football-sized rock on January 18, 2004, just three days after it successfully rolled off the lander. Scientists named the angular rock after the Adirondack mountain range in New York. The name "Adirondacks" is an Anglicized version of the Mohawk "ratirontaks", meaning "they eat trees", a derogatory name which the Mohawk historically applied to the Algonquian-speaking tribes of the Adirondack Mountains; when food was scarce, the Algonquians would eat the buds and bark of trees. The rock was selected as "Spirit"s first target because its dust-free, flat surface was ideally suited for grinding. Clean surfaces also are better for examining a rock's top coating. "Spirit" also returned microscopic images and Mössbauer spectrometer readings of Adirondack taken the day before the rover developed computer and communication problems on January 22, 2004. Both are unprecedented investigations of any rock on another planet. The microscopic images indicate Adirondack is a hard, crystalline rock. The peaks large and small in Adirondack's electromagnetic spectrum reveal that the minerals in the rock include olivine, pyroxene and magnetite - a common composition in volcanic basalt rocks on Earth. Adirondack turned out to be typical of the other rocks on the plains. "Spirit" rover's instruments determined that Adironack and other rocks of the plains contain the minerals pyroxene, olivine, plagioclase, and magnetite. These rocks can be classified in different ways. The amounts and types of minerals make the rocks primitive basalts—also called picritic basalts. The rocks are similar to ancient terrestrial rocks called basaltic komatiites. Rocks of the plains also resemble the basaltic shergottites, meteorites which came from Mars. One classification system compares the amount of alkali elements to the amount of silica on a graph; in this system, Gusev plains rocks lie near the junction of basalt, picrobasalt, and tephite.