Amenthes Quadrangle

The Amenthes quadrangle is one of a series of 30 quadrangle maps of Mars used by the United States Geological Survey (USGS) Astrogeology Research Program. The Amenthes quadrangle is also referred to as MC-14 (Mars Chart-14). The quadrangle covers the area from 225° to 270° west longitude and from 0° to 30° north latitude on Mars. Amenthes quadrangle contains parts of Utopia Planitia, Isidis Planitia, Terra Cimmeria, and Tyrrhena Terra.

The name Amenthes is the Egyptian word for the place where the souls of the dead go.

This quadrangle contains the Isidis basin, a location where magnesium carbonate was found by MRO. This mineral indicates that water was present and that it was not acidic. There are Dark slope streaks, troughs (fossae), and river valleys ( Vallis) in this quadrangle.

The Beagle 2 lander was about to land in the quadrangle, particularly in the eastern part of Isidis Planitia, in December 2003, when contact with the craft was lost. In January 2015, NASA reported the Beagle 2 had been found on the surface in Isidis Planitia (location is about ). High-resolution images captured by the Mars Reconnaissance Orbiter identified the lost probe, which appears to be intact. ( see discovery images here)

Craters

Some craters in the Amenthes region (as well as other parts of Mars) show ejecta around them that have lobes. It is believed that the lobed shape is caused by an impact into water or ice logged ground. Calculations suggest that ice is stable beneath the Martian surface.

At the equator the stable layer of ice might lie under as much as 1 kilometer of material, but at higher latitudes the ice may be just a few centimeters below the surface. This was proven when the landing rockets on the Phoenix lander blew away surface dust to reveal an ice surface. The larger an impact crater, the deeper its penetration, a large crater is more likely to have a lobate ejecta since it went down to the ice layer. When even small craters have lobes, the ice level is close to the surface. This idea would be very important for future colonists on Mars who would like to live near a source of water.

Impact craters generally have a rim with ejecta around them, in contrast volcanic craters usually do not have a rim or ejecta deposits. Sometimes craters will display layers. Since the collision that produces a crater is like a powerful explosion, rocks from deep underground are tossed unto the surface. Hence, craters can show us what lies deep under the surface. One crater in the Amenthes quadrangle is believed to be a source of nakhlite meteorites. A team of researchers found that these particular meteorites came from four different eruptions of lava because they showed different ages. The ages were measured by comparing isotopes of the element Argon. Since the ages vary from 93 to 1322 million years, the authors concluded that volcanoes grow much more slowly on Mars than the Earth. Many of the volcanoes on the Earth grow much quicker, as they form at plate boundaries. In contrast, Martian volcanoes probably form from plumes.

Image:Escalante Crater Wall.JPG, Escalante Crater wall, as seen by HiRISE Image on left is an enlargement.
Image:Onon Crater.JPG, Onon Crater, as seen by HiRISE. Scale bar is 500 meters long.
Image:Libya Montes Region.JPG, Libya Montes Region, as seen by HiRISE Image contains some sheer rock cliffs.
Wikidumartheraywest.jpg, Western side of Du Martheray Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter).
ESP 046046 2095craterandejecta.jpg, Crater and ejecta, as seen by HiRISE under HiWish program
46046 2095crater.jpg, Close view of crater and ejecta, as seen by HiRISE under HiWish program
46046 2095craterclose.jpg, Close view of crater, as seen by HiRISE under HiWish program
46046 2095craterejecta.jpg, Close view of crater ejecta, as seen by HiRISE under HiWish program
File:ESP 054551 2030craterlayers.jpg, Close view of layers in crater, as seen by HiRISE under HiWish program

File:ESP 057017 1975craterrim.jpg, Rocks at crater rim, as seen by HiRISE under HiWish program

Hebrus Valles

Hebrus Vales has tributaries, terraces, and teardrop shaped islands. The tear drop shape of the islands indicate what direction the water used to flow. The terraces may be caused by different layers of rocks or from the water being at different levels. These features are common for the rivers of the Earth.

Image:Hebrus Valles.JPG, Hebrus Valles, as seen by THEMIS. Direction of flow was determined by shape of streamlined islands. Terraces may have been due to separate flood events.
Image:Hebrus Valles from Themis.JPG, Hebrus Valles, as seen from Themis. Since discontinuous pits and troughs are present, collapse of material into a void may have caused the troughs.

Streamlined shapes

Streamlined shapes are formed from erosion by flowing water.

ESP 045860 2085streamlined.jpg, Wide view of streamlined shapes, as seen by HiRISE under HiWish program
ESP 045860 2085streamlinedbottom.jpg, Close view of streamlined shapes, as seen by HiRISE under HiWish program Arrow indicates the direction of past flowing water.
ESP 045860 2085streamlinedmiddle.jpg, Close view of streamlined shapes, as seen by HiRISE under HiWish program
ESP 045860 2085streamlinedtop.jpg, Close view of streamlined shapes, as seen by HiRISE under HiWish program
ESP 045860 2085streamlineduppertop.jpg, Close view of streamlined shapes, as seen by HiRISE under HiWish program
45860 2085close.jpg, Close view of streamlined shape, as seen by HiRISE under HiWish program
File:ESP 054800 2075streamlined.jpg, Streamlined shapes formed by flowing water, as seen by HiRISE under HiWish program

Cones

ESP 048023 2040conestroughs.jpg, Wide view of cones and trough, as seen by HiRISE under HiWish program
48023 2040coneclose.jpg, Cone next to a trough, as seen by HiRISE under HiWish

ESP 048050 2025cones.jpg, Cones, as seen by HiRISE under HiWish
Image:ESP 035008 2010cones.jpg, Line of cones, as seen by HiRISE under HiWish program

ESP 049975 2045cones.jpg, Cones, as seen by HiRISE under HiWish program White arrows point to some of the cones.

49975 2045cones.jpg, Close view of cones, as seen by HiRISE under HiWish program

File:570770 2100cones.jpg, Close view of cones, as seen by HiRISE under HiWish program

Mesas

Mesas form when erosion has removed much of the surrounding ground. They are the remains of material that once covered a wide area.

ESP 050858 2025mesa.jpg, Layered mesa that appears to have a streamlined shape, as seen by HiRISE under HiWish program A channel has cut through a lower layer.
ESP 044832 2035mesa.jpg, Layered mesa, as seen by HiRISE under HiWish program

Fossae

The Amenthes quadrangle is also home to troughs (long narrow depressions) called fossae in the geographical language used for Mars. These troughs form when the crust is stretched until it breaks. The stretching can be due to the large weight of a nearby volcano.

Image:ESP_024921fan.jpg, Wall of trough of Amenthes Fossae, as seen by HiRISE under HiWish program.
Image:ESP 036801 2015amenthespits.jpg, Large pits, as seen by HiRISE under HiWish program
Image:ESP 036023 2025amenthestroughtop.jpg, Trough, as seen by HiRISE under HiWish program
Image:Hephaestus Fossae Two Vews.JPG, Hephaestus Fossae Two Views, as seen by HiRISE. Picture on right lies to the top (north) of other picture. Fossa (geology) often form by material moving into an underground void.

ESP 051781 2035troughs.jpg, Troughs, as seen by HiRISE under HiWish program

File:ESP 057834 2005troughmesa.jpg, Troughs cutting through mesa, as seen by HiRISE under HiWish program

Channels

File:ESP 057241 1825channels.jpg, Group of channels, as seen by HiRISE under HiWish program

Image:Granicus Vallis Tributary.JPG, Granicus Vallis Tributary, as seen by HiRISE.
ESP 046586 2035ejectachannel.jpg, Channel along edge of crater ejecta, as seen by HiRISE under HiWish program Arrows show channel.
File:ESP 054775 1825channels.jpg, Channels, as seen by HiRISE under HiWish program

Other landscape features in Amenthes quadrangle

Image:Amenthes map.JPG, Map of Amenthes quadrangle. The northwest part includes Isidis Planitia. Escalante Crater is near the equator.
Image:Lobate ejecta in Amenthes.JPG, Lobate ejecta in Amenthes. Large crater has lobate ejecta, smaller craters do not show such ejecta since the ice layer was not penetrated by the smaller impacts.

Image:Amenthes Fossae Region.JPG, Amenthes Fossae Region, as seen by HiRISE.
Image:Tinjar Vallis.JPG, Tinjar Vallis, as seen by THEMIS. Color is enhanced to show differences.
Image:Scamander Vallis.JPG, Scamander Vallis. Dark Slope Streaks may be seen in the image. The darker the streak, the younger it is.

Other Mars quadrangles

Interactive Mars map

See also

* Climate of Mars
* Dark slope streaks
* Fossa (geology)
* Geology of Mars
* HiRISE
* HiWish program
* Hydrothermal circulation
* Impact crater
* List of quadrangles on Mars
* List of craters on Mars
* Ore resources on Mars
* Vallis
* Water on Mars

References

External links

{{DEFAULTSORT:Amenthes Quadrangle

Mars