Adirondack (Mars)
 | This article needs to beupdated.(November 2010) |
  (Above) An approximatetrue-colorview of "Adirondack"rock,taken bySpirit's pancam. (Right) Digital camera image (fromSpirit'sPancam) of "Adirondack" rock after aRATgrind (Spirit's rock-grinding tool) | |
| Feature type | Rock |
|---|---|
| Coordinates | 14°36′S175°30′E/ 14.6°S 175.5°E |
Adirondackis the nickname forMars Exploration RoverSpirit's first targetrock.[citation needed]Scientists chose Adirondack to beSpirit's first target rock after considering another, called Sashimi, that would have been a shorter, straight-ahead drive.[citation needed]Spirittraversed the sandy martian terrain atGusev Craterto arrive in front of thisfootball-sized rock on January 18, 2004, just three days after it successfully rolled off thelander.[citation needed]
Scientists named the angular rock after theAdirondack mountain rangeinNew York.
The rock was selected asSpirit'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.[citation needed]Spiritalso returnedmicroscopicimages 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 anotherplanet.The microscopic images indicate Adirondack is a hard,crystallinerock. The peaks large and small in Adirondack'selectromagnetic spectrumreveal that themineralsin the rock includeolivine,pyroxeneandmagnetite- a common composition in volcanicbasaltrocks on Earth.[citation needed]
Adirondack turned out to be typical of the other rocks on the plains.Spiritrover's instruments determined that Adironack and other rocks of the plains contain the mineralspyroxene,olivine,plagioclase,andmagnetite.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 basaltickomatiites.Rocks of the plains also resemble the basalticshergottites,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 tephrite. The Irvine-Barager classification calls them basalts.[1] Adirondack has been very slightly altered, probably by thin films of water because they are softer and contain veins of light colored material that may be bromine compounds, as well as coatings or rinds. Small amounts of water may have gotten into cracks inducing mineralization processes.[2][3] Coatings on the rocks in the plains may have occurred when rocks were buried and interacted with thin films of water and dust.[citation needed] One sign that they were altered was that it was easier to grind these rocks compared to the same types of rocks found on Earth.[citation needed]
