Astronomy:Russell (Martian crater)
The Russell Crater dune field is covered seasonally by carbon dioxide frost. Numerous dark dust devil tracks can be seen meandering across the dunes.
Russell is a crater on Mars, located in the Noachis quadrangle at 54.9° south latitude and 347.6° west longitude. It measures approximately 135 kilometers in diameter and was named after American astronomer Henry Norris Russell (1877–1957).
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. Another idea is that chunks of dry ice form on the dunes during the cold winter, then slide down in the spring when it is warmer. Experiments have demonstrated that carbon dioxide from the thawing dry ice forms a lubricating layer under pieces of dry ice, making it easy for the process to take place.
Gullies on dunes
Gullies are found on some dunes. These are somewhat different from gullies in other places, like the walls of craters. Gullies on dunes seem to keep the same width for a long distance and often just end with a pit, instead of an apron. Many of these gullies are found on dunes in Russell (Martian crater).
Close view of the end of gullies in Russell Crater, as seen by HiRISE Note: These type of gullies do not usually end with an apron. The location is Noachis quadrangle.
- "Gazetteer of Planetary Nomenclature | Russell". International Astronomical Union. http://planetarynames.wr.usgs.gov/Feature/5236.
- Reiss, D, R. Jaumann. 2003. Recent debris flows on Mars: Seasonal observations of the Russell Crater dune field. Geophysical Research Letters: 30, 1321.
- McEwen, A., et al. 2017. Mars The Pristine Beauty of the Red Planet. University of Arizona Press. Tucson.
Original source: https://en.wikipedia.org/wiki/ Russell (Martian crater). Read more