Adirondack (Mars)

{{Short description|Boulder on Mars}} {{update|date=November 2010}} {{Infobox feature on celestial object |name = Adirondack Rock |image = [[File:Adirondacksquare.jpg|{{#expr: (200 * (316 / 196)) round 0}}px]][[File:Rat post grind.jpg|right|{{#expr: (200 * (505 / 494)) round 0}}px]] |caption = (Above) An approximate [[24-bit color|true-color]] view of "Adirondack" [[Rock (geology)|rock]], taken by ''Spirit''{{'}}s pancam.<br />(Right) Digital camera image (from ''Spirit''{{'}}s [[Pancam]]) of "Adirondack" rock after a [[Rock Abrasion Tool|RAT]] grind (''Spirit''{{'}}s rock-grinding tool) |type = [[Rock (geology)|Rock]] |coordinates = {{coord|14.6|S|175.5|E|globe:mars_type:landmark|display=inline,title}} }} '''Adirondack''' is the nickname for [[Mars Exploration Rover Mission|Mars Exploration Rover]] [[MER-A|''Spirit'']]'s first target [[rock (geology)|rock]].<ref>{{Cite web |title=Spirit Drives to First Target - NASA |url=https://www.nasa.gov/image-article/spirit-drives-first-target/ |access-date=2026-04-01 |language=en-US}}</ref> Scientists chose Adirondack to be ''Spirit''{{'}}s first target rock after considering another, called Sashimi, that would have been a shorter, straight-ahead drive.<ref>{{Cite web |title=Spirit Drives to a Rock Called 'Adirondack' for Close Inspection |url=https://www.jpl.nasa.gov/news/spirit-drives-to-a-rock-called-adirondack-for-close-inspection/ |access-date=2026-04-01 |website=NASA Jet Propulsion Laboratory (JPL) |language=en-US}}</ref> ''Spirit'' traversed the sandy Martian terrain at [[Gusev Crater]] to arrive in front of this [[football (ball)|football]]-sized rock on January 18, 2004, just three days after it successfully rolled off the [[Lander (spacecraft)|lander]].<ref name=":0">{{Cite web |date=2004-01-19 |title=“They of the Great Rocks” - NASA Science |url=https://science.nasa.gov/photojournal/they-of-the-great-rocks/ |access-date=2026-04-01 |language=en-US}}</ref>

Scientists named the angular rock after the [[Adirondack Mountains|Adirondack mountain range]] in [[New York (state)|New York]].

[[File:Rockgusev.jpg|thumb|left|200px|Cross-section of a typical rock from the plains of [[Gusev crater]] - most rocks contain a coating of dust - water-deposited veins are visible.]] 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.<ref name=":0" /> ''Spirit'' also returned [[Microscope|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.<ref>{{Cite web |title=Spaceflight Now {{!}} Destination Mars {{!}} Thousands of files deleted on Spirit to fix computer trouble |url=https://spaceflightnow.com/mars/mera/040201spirit.html |access-date=2026-04-01 |website=spaceflightnow.com}}</ref>

Adirondack turned out to be typical of the other rocks on the plains. [[Spirit Rover|''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 [[shergottite]]s, 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.<ref>McSween, etal. 2004. "Basaltic Rocks Analyzed by the Spirit Rover in Gusev Crater". ''Science'' : 305. 842-845</ref> 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.<ref>McSween, etal. 2004. Basaltic Rocks Analyzed by the Spirit Rover in Gusev Crater. ''Science'' : 305. 842-845</ref><ref>Arvidson, R. E., et al. (2004) ''Science'', 305, 821-824</ref> Coatings on the rocks in the plains may have occurred when rocks were buried and interacted with thin films of water and dust.<ref name=":1">{{Cite web |title=Aeolis quadrangle |url=https://marspedia.org/Aeolis_quadrangle |access-date=2026-04-01 |website=Marspedia |language=en}}</ref> 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.<ref name=":1" /> {{Clear}}

== See also == {{div col|colwidth=20em}} * [[Aeolis quadrangle]] * [[Composition of Mars]] * [[List of rocks on Mars]] * [[Scientific information from the Mars Exploration Rover mission]] {{div col end}}

== References == {{Reflist|30em}}

== External links == * [https://mars.nasa.gov/mer/index.cfm Official Mars Rovers site] * [https://mars.nasa.gov/mer/newsroom/pressreleases/20040119a.html January 19, 2004 JPL press release]

[[Category:Rocks on Mars]]