Home Plate (Mars)
{{Short description|Extraterrestrial Plateau}}
{{Infobox feature on celestial object
|name = Home Plate
|image = 200px
|caption = HiRISE image of the "Home Plate" rock outcrop.
|type = Rock outcrop
|coordinates = {{coord|14.6|S|175.5|E|globe:mars_type:landmark|display=inline,title}}
}}
Home Plate is a plateau roughly 90 m across within the Columbia Hills, Mars. It is informally named for its similarity in shape to a baseball home plate. Home Plate is a rocky outcrop that appears to show layered features.
The plateau has been extensively studied by Spirit, one of the Mars Exploration Rovers, since 2006. The rover became stuck in loose granular material alongside the northeast side of the plateau. The rover last communicated with Earth on March 22, 2010.{{cite web|url=http://www.nasa.gov/mission_pages/mer/multimedia/pia15037.html|title=Spirit Remains Silent at Troy|access-date=April 21, 2012|archive-date=November 24, 2012|archive-url=https://web.archive.org/web/20121124045328/http://www.nasa.gov/mission_pages/mer/multimedia/pia15037.html|url-status=dead}}
Exploration
Spirit arrived at Home Plate on sol 744 (February 7, 2006) and has completed a scientific investigation with her robotic arm before moving to Low Ridge Haven due to power concerns. She returned on sol 1126 to resume those studies.
Spirit spent her third Martian winter on Home Plate's north edge.{{cite web|url=https://www.newscientist.com/article/dn12884-mars-rover-spirit-to-head-north-for-the-winter.html|title=Mars rover Spirit to head north for the winter|author=Maggie McKee|access-date=December 26, 2007}}
{{Wide image|Sol594A P2281 L257atc-A597R1 br2.jpg|600px|Home Plate (upper center), as seen from the summit of Husband Hill.}}
Origins
Scientists now believe that Home Plate is an explosive volcanic deposit. It is surrounded by deposits of basalt, which are believed to have exploded on contact with water. The presence of brine is further supported by the high concentration of chloride ions in the surrounding rocks. The presence of bomb sags (laminae typically found in beds of volcanish ash) seems to confirm this hypothesis.{{cite journal|journal=Science|title=Pyroclastic Activity at Home Plate in Gusev Crater, Mars|pages=738–742|volume=316|doi=10.1126/science.1139045|date=2007|pmid=17478719|issue=5825|bibcode = 2007Sci...316..738S |last2=Aharonson|first2=O.|last3=Clark|first3=B.C.|last4=Cohen|first4=B. A.|last5=Crumpler|first5=L.|last6=De Souza|first6=P. A.|last7=Farrand|first7=W. H.|last8=Gellert|first8=R.|last9=Grant|first9=J.|last10=Grotzinger|first10=J. P.|last11=Haldemann|first11=A. F. C.|last12=Johnson|first12=J. R.|last13=Klingelhofer|first13=G.|last14=Lewis|first14=K. W.|last15=Li|first15=R.|last16=McCoy|first16=T.|last17=McEwen|first17=A. S.|last18=McSween|first18=H. Y.|last19=Ming|first19=D. W.|last20=Moore|first20=J. M.|last21=Morris|first21=R. V.|last22=Parker|first22=T. J.|last23=Rice|first23=J. W.|last24=Ruff|first24=S.|last25=Schmidt|first25=M.|last26=Schroder|first26=C.|last27=Soderblom|first27=L. A.|last28=Yen|first28=A.|last1=Squyres|first1=S.|author-link1=Steve Squyres|url=https://authors.library.caltech.edu/36849/7/Squyres.SOM.pdf|hdl=2060/20070016011|s2cid=9687521 |hdl-access=free}}
A patch of 90% pure opaline silicon dioxide was unearthed by Spirit in the vicinity of Home Plate. The patch is believed to be formed in acidic hydrothermal conditions, which supports the theory that Home Plate is of an explosive volcanic origin. Water is also present as mineral hydrates.{{cite web|url=http://www.nasa.gov/mission_pages/mer/mer-20070521.html|title=Mars Rover Spirit Unearths Surprise Evidence of Wetter Past|access-date=May 30, 2007|archive-date=March 8, 2013|archive-url=https://web.archive.org/web/20130308054606/http://www.nasa.gov/mission_pages/mer/mer-20070521.html|url-status=dead}}{{cite journal|journal=Science|volume=320|pages=1063–1067|title=Detection of Silica-Rich Deposits on Mars|doi=10.1126/science.1155429|date=2008|pmid=18497295|issue=5879|display-authors=8|last1=Squyres|first1=SW|last2=Arvidson|first2=RE|last3=Ruff|first3=S|last4=Gellert|first4=R|last5=Morris|first5=RV|last6=Ming|first6=DW|last7=Crumpler|first7=L|last8=Farmer|first8=JD|last9=Marais|first9=DJ|last10=Yen|first10=A.|last11=McLennan|first11=S. M.|last12=Calvin|first12=W.|last13=Bell|first13=J. F.|last14=Clark|first14=B. C.|last15=Wang|first15=A.|last16=McCoy|first16=T. J.|last17=Schmidt|first17=M. E.|last18=De Souza|first18=P. A.|bibcode = 2008Sci...320.1063S|s2cid=5228900 }}
Since 2008, scientists believe that this formation is an example of an eroded, ancient, and extinct fumarole.{{Cite journal |last=Morris |first=R. V. |last2=Ming |first2=D. W. |last3=Gellert |first3=R. |last4=Yen |first4=A. S. |last5=Clark |first5=B. C. |last6=Graff |first6=T. G. |last7=Arvidson |first7=R. E. |last8=Squyres |first8=S. W. |author9=Athena |author10=CRISM Science Teams |date=2008 |title=The Hydrothermal System at Home Plate in Gusev Crater, Mars: Formation of High Silica Material by Acid-Sulfate Alteration of Basalt |url= |journal=Lunar and Planetary Science |volume=39 |pages=2208 |bibcode=2008LPI....39.2208M |bibcode-access=free}}
Gallery
File:Home plate.JPG|Spirit imager moves towards Home Plate.
File:Bomb sag on Mars.jpg|Bomb sag
File:Home plate anim.gif|Curious rock, "animated" via wiggle stereoscopy.
See also
{{wikinews|Spirit Rover on Mars finds water made 'silica-rich soil'}}
References
{{reflist|30em}}
External links
- [https://mars.nasa.gov/ Nasa's Mars Exploration Program]
- [https://web.archive.org/web/20051103223725/http://marsrovers.nasa.gov/mission/traverse_maps.html Current position of the Mars rovers] - Home Plate is visible, with Spirit{{'}}s journey around it.
- [http://www.planetary.org/blog/article/00000452/ The Planetary Society Weblog: Home, Sweet Home for Spirit] {{Webarchive|url=https://web.archive.org/web/20060215185421/http://www.planetary.org/blog/article/00000452/ |date=2006-02-15 }}
- [https://mars.nasa.gov/mer/index.cfm Official Mars Rovers site]
{{Features visited by Spirit rover}}
{{Mars}}
{{Portal bar|Solar System}}