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Argyre quadrangle

Argyre quadrangle
USGS-Mars-MC-26-ArgyreRegion-mola.png
Map of Argyre quadrangle from Mars Orbiter Laser Altimeter (MOLA) data. The highest elevations are red and the lowest are blue.
Coordinates 47°30′S 30°00′W / 47.5°S 30°W / -47.5; -30Coordinates: 47°30′S 30°00′W / 47.5°S 30°W / -47.5; -30

The Argyre quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Argyre quadrangle is also referred to as MC-26 (Mars Chart-26). It contains Argyre Planitia and part of Noachis Terra.

The word Argyre is named after a legendary silver at the mouth of the Ganges--[Arakan, Berma.

The Argyre quadrangle covers the area from 0° to 60° west longitude and from 30° to 65° south latitude on Mars. It contains Galle crater, which resembles a smiley face and the Argyre basin, a giant impact crater. Research published in the journal Icarus has found pits in Hale Crater that are caused by hot ejecta falling on ground containing ice. The pits are formed by heat forming steam that rushes out from groups of pits simultaneously, thereby blowing away from the pit ejecta. Many steep slopes in this quadrangle contain gullies, which are believed to have formed by relatively recent flows of water.

Gullies are common in some latitude bands on Mars. Usually, martian gullies are found on the walls of craters or troughs, but Charitum Montes, a group of mountains, has gullies in some areas (See the image below).

Gullies occur on steep slopes, especially on the walls of craters. Gullies are believed to be relatively young because they have few, if any craters. Moreover, they lie on top of sand dunes which themselves are considered to be quite young. Usually, each gully has an alcove, channel, and apron. Some studies have found that gullies occur on slopes that face all directions, others have found that the greater number of gullies are found on poleward facing slopes, especially from 30-44 S.

Although many ideas have been put forward to explain them, the most popular involve liquid water coming from an aquifer, from melting at the base of old glaciers, or from the melting of ice in the ground when the climate was warmer. Because of the good possibility that liquid water was involved with their formation and that they could be very young, scientists are excited. Maybe the gullies are where we should go to find life.


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