Last Chance is a layered rock outcrop found within the
Margaritifer Sinus quadrangle
The Margaritifer Sinus quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Margaritifer Sinus quadrangle is also referred to as MC-19 (Mars Chart-19) ...
(MC-19) region of the planet
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
, discovered by the
Mars Exploration Rover
NASA's Mars Exploration Rover (MER) mission was a robotic space mission involving two Mars rovers, ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'', exploring the planet Mars. It began in 2003 with the launch of the two rover ...
''
Opportunity
Opportunity may refer to:
Places
* Opportunity, Montana, an unincorporated community, United States
* Opportunity, Nebraska, an unincorporated community, United States
* Opportunity, Washington, a former census-designated place, United States
* 3 ...
'' in March 2004. The rock lies within the outcrop near the rover's landing site at
Meridiani Planum
The Meridiani Planum (alternately Meridiani plain, Meridiani plains, Terra Meridiani, or Terra Meridiani plains) is either a large plain straddling the equator of Mars and covered with a vast number of spherules containing a lot of iron oxide or ...
, Mars.
Images returned show evidence for a geologic feature known as
ripple
Ripple may refer to:
Science and technology
* Capillary wave, commonly known as ripple, a wave traveling along the phase boundary of a fluid
** Ripple, more generally a disturbance, for example of spacetime in gravitational waves
* Ripple (electri ...
cross-stratification
In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The original ...
. At the base of the rock, layers can be seen dipping downward to the right. The bedding that contains these dipping layers is only one to two centimeters (0.4 to 0.8 inches) thick. In the upper right corner of the rock, layers also dip to the right, but exhibit a weak "concave-up" geometry. These two features—the thin, cross-stratified bedding combined with the possible concave geometry—suggest small ripples with sinuous crest lines. Although
wind
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few hou ...
can produce ripples, they rarely have sinuous crest lines and never form steep, dipping layers at such a small scale. The most probable explanation for these ripples is that they were formed in the presence of moving
water
Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...
.
See also
*
List of rocks on Mars
This is an alphabetical list of named rocks (and meteorites) found on Mars, by mission. This list is a sampling of rocks viewed, and is not an exhaustive listing. A more complete listing may be found on the various NASA mission web sites. This lis ...
*
List of surface features of Mars imaged by ''Opportunity''
References
External links
Nasa's Mars Exploration Program
Mars Exploration Rover mission
Rocks on Mars
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