Green is an impact crater in the
Argyre quadrangle of
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury. In the English language, Mars is named for the Roman god of war. Mars is a terrestrial planet with a thin at ...
. It is named after
Nathan E. Green, a British astronomer (1823-1899).
Description
Debris flows have been observed on some of the
dunes in this crater. Some researchers believe that they may be caused by liquid water. Liquid water could be stable for short periods of time in the summer in the southern hemisphere of Mars. These gully-like debris flows may be due to small amounts of ice melting.
[Reiss, D, R. Jaumann. 2003. Recent debris flows on Mars: Seasonal observations of the Russell Crater dune field. Geophysical Research Letters: 30, 1321.]
Wikigreeneast.jpg, East side of Green crater, as seen by CTX camera (on MRO).
Wikigreen.jpg, Green crater, as seen by CTX camera. Dark dots are dunes.
Wikigreendunes.jpg, Dunes in Green crater, as seen by CTX camera. This is an enlargement of the previous image. Thin dark lines are dust devil tracks
Martian dust devils (dust devils on Mars) were first photographed by the Viking orbiters in the 1970s. In 1997, the Mars Pathfinder lander detected a dust devil passing over it. In the first image below, photographed by the Mars Global Surveyor, ...
. The crater on the right is within Green crater. Some old glaciers are visible as arc-shaped ridges. An arrow points to one of the glaciers.
Image:Close-up of Green Crater Gullies.JPG, Close-up of gullies in Green crater, as seen by HiRISE.
Dunes
Barchan dunes are present in Green crater and visible in pictures below. When there are perfect conditions for producing sand dunes, steady wind in one direction and just enough sand, a barchan sand dune forms. Barchans have a gentle slope on the wind side and a much steeper slope on the lee side where horns or a notch often forms.
See also
*
List of craters on Mars
*
Gullies on Mars
References
{{Portal bar, Solar System
Argyre quadrangle
Impact craters on Mars