Rupes Tenuis () is a

Martian Mars, the fourth planet from the Sun, has appeared as a setting in works of fiction since at least the mid-1600s. Trends in the planet's portrayal have largely been influenced by advances in planetary science. It became the most popular celes ...

north polar scarp. It is named after one of the

classical albedo features on Mars The classical albedo features of Mars are the light and dark features that can be seen on the planet Mars through an Earth-based telescope. Before the age of space probes, several astronomers created maps of Mars on which they gave names to the fe ...

. Its name was officially approved by

IAU The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

in 1988. It extends from latitude 74.94°N to 82.2°N and from longitude 242.12°E to 300.77°E (59.23°W – 117.88°W). Its centre is located at latitude 81.6°N longitude 85.47°W. It marks the outer perimeter of Planum Boreum from longitude 242.12°E to 300.77°E, and it is formed by the eastern extension of the Olympia Cavi, a series of local troughs and depressions, which become longer and deeper as they merge to create the Rupes Tenuis scarp formation. The scarp is located to the west of Chasma Boreale, at the base of

Planum Boreum Planum Boreum (Latin: "the northern plain") is the northern polar plain on Mars. It extends northward from roughly 80°N and is centered at . Surrounding the high polar plain is a flat and featureless lowland plain called Vastitas Borealis which ...

, and its height varies from a few hundred metres to a maximum of approximately 1000 metres.

Local topography

USGS-Mars-MC-1 Map of Planum Boreum cropped

Immediately to the south of Rupes Tenuis, approximately at 285ºE, lies

Abalos Mensa Abalos Mensa is a wedge-shaped mound, or mensa and one of the named features in the vicinity of Planum Boreum, the Martian North pole. It is named after one of the classical albedo features on Mars. Its name was officially approved by IAU in 2 ...

, a convex formation of approximately 180 kilometer span, shaped like a wedge when viewed from above. The dune field of Abalos Undae continues in a southwestward direction after it emerges from the western end of a narrow channel separating Rupes Tenuis from Abalos Mensa. Two named craters are located in the immediate area of Rupes Tenuis;

Crotone Crotone (; ; or ) is a city and ''comune'' in Calabria, Italy. Founded as the Achaean colony of Kroton ( or ; ), it became a great Greek city, home of the renowned mathematician-philosopher Pythagoras amongst other famous citizens, and one ...

, located at 82.2ºN, 290.0ºE with a 6.4 km diameter, is situated at the channel separating the scarp from Abalos Mensa, and Boola, located at 81.1ºN, 254.2ºE, with a 17 km diameter, is found close to the western boundary of the Rupes Tenuis scarp. West of Abalos Mensa, parallel to and south of the Rupes Tenuis scarp, runs a narrow, low-altitude plain, named Tenuis Mensa, which exhibits a southward slope.

Erosion characteristics

PSP 010171 2630 MIRB Upper Rupes Tenuis Unit Exposed Northwest of Crotone Crater

The proposed erosion mechanism for the polar basal unit in general, and Rupes Tenuis in particular, are

katabatic wind A katabatic wind (named ) is a downslope wind caused by the flow of an elevated, high-density air mass into a lower-density air mass below under the force of gravity. The spelling catabatic is also used. Since air density is strongly dependent o ...

s (From

Greek Greek may refer to: Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group *Greek language, a branch of the Indo-European language family **Proto-Greek language, the assumed last common ancestor of all kno ...

katabasis A katabasis or catabasis (; ) is a journey to the underworld. Its original sense is usually associated with Greek mythology and classical mythology more broadly, where the protagonist visits the Greek underworld, also known as Hades. The term is ...

, "descent", i.e. strong winds descending from Planum Boreum), and solar

ablation Ablation ( – removal) is the removal or destruction of something from an object by vaporization, chipping, erosion, erosive processes, or by other means. Examples of ablative materials are described below, including spacecraft material for as ...

. These mechanisms are also considered responsible for the modern-day erosion and retreat of the Rupes Tenuis scarp, the existence of conical mounds and promontories in the immediate vicinity of the scarp, and the creation of the narrow channels that separate Abalos Mensa from the scarp. This erosion process is theorised to have existed since the Late Amazonian period on Mars, and it is considered to have contributed to the continuous retreat of the polar scarp from an older southern latitude as low as 74ºN. It is further theorised that the Rupes Tenuis

stratigraphic Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithost ...

unit may have been a paleo-plateau that descended further South than the present-day Rupes Tenuis scarp. Geological formations in the vicinity of the scarp, such as mounds, are considered to have been formed by erosion mechanisms rather than volcanic activity. The horizontal attitude (inclination) of the layers of the Rupes Tenuis unit, further indicates the non-volcanic origin of these formations, since layers of volcanic origin are not typically horizontal. Nearby formations such as

Abalos Colles Abalos Colles (Latin for "Abalos Hills") is a Stratum, stratified fragment of the Rupes Tenuis basal unit of Planum Boreum, located south of the Rupes Tenuis scarp and west of the Escorial crater. It contains 16 mounds. Abalos Colles is one of t ...

— a group of five, flat or concave top, mounds, less than 700 m high and less than 1 km in diameter — are considered to be erosional remnants of a once-continuous stratigraphic unit, the Rupes Tenuis unit.

Images by NASA and ESA

File:Rupes Tenuis ESA214031.jpg, The Rupes Tenuis scarp with Abalos Mensa at the top of the picture. Picture was taken by the

Mars Express ''Mars Express'' is a space exploration mission by the European Space Agency, European Space Agency (ESA) exploring the planet Mars and its moons since 2003, and the first planetary mission attempted by ESA. ''Mars Express'' consisted of two ...

orbiter of the

European Space Agency The European Space Agency (ESA) is a 23-member International organization, international organization devoted to space exploration. With its headquarters in Paris and a staff of around 2,547 people globally as of 2023, ESA was founded in 1975 ...

File:ESP 028303 2620 RED.NOMAP Rupes Tenuis.jpg, Rupes Tenuis scarp File:PSP 009012 2610 MIRB Boola Crater Ejecta Exposed on Rupes Tenuis.jpg, Boola crater ejecta exposed on Rupes Tenuis File:PIA20607 Rupes Tenuis scarp.jpg, Rupes Tenuis is the strip in the middle of the image. The polar cap is on the top side of the image with the lower elevation at the bottom. File:PSP 009406 2600 MIRB Exposed Rupes Tenuis of the Southern Margin of Hyperborea Lingula.jpg, Exposed Rupes Tenuis of the southern margin of Hyperborea Lingula File:ESP 028369 2615 MIRB Rupes Tenuis.jpg, Rupes Tenuis File:PSP 010092 2625 MIRB Basal Rupes Tenuis Unit Exposed North of Abalos Mensa.jpg, Basal Rupes Tenuis unit exposed north of Abalos Mensa File:ESP 019454 2610 MIRB Contact between Rupes Tenuis Scarp and Buried Polygon.jpg, Contact between Rupes Tenuis scarp and buried polygon File:ESP 027498 2625 MRGB Rupes Tenuis Promontory.jpg, Rupes Tenuis Promontory File:ESP 028303 2620 MIRB Rupes Tenuis.jpg, Rupes Tenuis File:ESP 028237 2620 MIRB Rupes Tenuis.jpg, Rupes Tenuis File:ESP 017793 2625 MIRB Interaction between Abalos Mensa and Rupes Tenuis Dunes.jpg, Interaction between Abalos Mensa and Rupes Tenuis dunes File:ESP 046170 2615 MIRB. Rupes Tenuis Scarp.jpg, Rupes Tenuis scarp File:ESP 017832 2625 MIRB Basal Rupes Tenuis Unit Exposed North of Abalos Mensa.jpg, Basal Rupes Tenuis unit exposed north of Abalos Mensa File:ESP 034500 2620 RED North Polar Scarp in Abalos Undae with Basal Exposure and Dunes black and white.jpg, North Polar scarp in Abalos Undae with basal exposure and dunes File:ESP 034500 2620 RED North Polar Scarp in Abalos Undae with Basal Exposure and Dunes black and white with scale.jpg, North Polar scarp in Abalos Undae with basal exposure and dunes and distance scale

References

{{Portal bar, Solar System Cliffs on Mars Mare Boreum quadrangle