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.
Exploration
''Spirit'' arrived at Home Plate on
sol
Sol or SOL may refer to:
Astronomy
* The Sun
Currency
* SOL Project, a currency project in France
* French sol, or sou
* Argentine sol
* Bolivian sol, the currency of Bolivia from 1827 to 1864
* Peruvian sol, introduced in 1991
* Peruvian 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.
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 ion
The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts ...
s in the surrounding rocks. The presence of
bomb sag
Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition.
Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different partic ...
s (laminae typically found in beds of volcanish ash) seems to confirm this hypothesis.
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
hydrate
In chemistry, a hydrate is a substance that contains water or its constituent elements. The chemical state of the water varies widely between different classes of hydrates, some of which were so labeled before their chemical structure was understo ...
s.
Since 2008, scientists believe that this formation is an example of an eroded, ancient, and extinct
fumarole.
[The Hydrothermal System at Home Plate in Gusev Crater, Mars, R.V.Morris, S.W.Squyres, -et al., Lunar & Planetary Science XXXIX(2008)]
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
*
List of rocks on Mars
References
External links
Nasa's Mars Exploration Program
- Home Plate is visible, with ''Spirit''s journey around it.
The Planetary Society Weblog: Home, Sweet Home for ''Spirit''
Official Mars Rovers site
{{Portal bar, Solar System
Rocks on Mars
Fumaroles
Mars Exploration Rover mission