Eberswalde (crater)
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| Eberswalde crater | |
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| Coordinates | 24° S, 33° W |
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| Diameter | 65.3 km |
| Depth | approx 800 m |
| Discoverer | Michael C. Malin and Ken Edgett |
| Eponym | Eberswalde, Brandenburg, Germany |
Eberswalde crater, formerly known as Holden NE crater, is a partially buried impact crater in Margaritifer Terra, Mars. The 65.3 km diameter crater, centered at 24°S, 33°W, is named after the German town of the same name, in accordance with the International Astronomical Union's rules for planetary nomenclature.[1] It is a proposed landing site for the future Mars rover, Mars Science Laboratory.[2]
Landforms in the crater provide strong evidence of the prior existence of flowing water on Mars.
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[edit] Eberswalde Delta
The crater contains a fossilized and exhumed delta which was formed by the flow of a liquid, most likely water. The series of valleys leading into the delta "drain" an area of approximately 4000 km². The surface area of the delta is 115 km², measuring 13 km by 11 km. The delta was discovered by Michael Malin and Kenneth Edgett of Malin Space Science Systems through imagery taken by the Mars Global Surveyor in 2003.
The delta also provides unambiguous evidence that some Martian sedimentary rocks have been deposited in a liquid. The meandering of the channels provides evidence to support this. Additional sediments were deposited on top of the delta, burying it. The deposits in the channels formed sedimentary rock. As the surrounding softer sediments were eroded away, the delta was exhumed, but inverted.[3][4]
Based on an estimate by Moore et. al in 2003 of flow volume to the crater at 700 m3/s, it is estimated that it would take twenty years to completely fill the crater, ignoring evaporation and infiltration. However, this is unlikely because it is hypothesized that the delta was not formed in a permanent lake but rather a series of short lacustrine episodes on the order of years. This suggests that the Martian climate at the Noachian epoch time of formation was characterized by a series of short, wet spells rather than a sustained wet climate.[5][6]
[edit] External links
- HiRISE image of Eberswalde Delta (warning: large images)
- MSSS page about the discovery
[edit] See also
- Mars Science Laboratory
- Geography of Mars
- River delta - the terrestrial equivalent
[edit] References
- ^ Gazetteer of Planetary Nomenclature. Retrieved on 2006-12-06.
- ^ The Eberswalde deltaic complex as a high science-return target. Retrieved on 2006-12-06.
- ^ 8 Years at Mars #6: Fossil Delta in Eberswalde Crater. Retrieved on 2006-12-06.
- ^ Michael C. Malin; Kenneth S Edgett (2003). "Evidence for persistent flow and aqueous sedimentation on Mars". Science 302: 1931–1934. doi:.
- ^ Kevin W. Lewis; Oded Aharonson (2006). "Stratigraphic analysis of the distributary fan in Eberswalde crater using stereo imagery". Journal of Geophysical Research 111: E06001. doi:.
- ^ Jeffrey M. Moore; Alan D. Howard, William D. Dietrich, Paul M. Schenk (2003). "Martian layered fluvial deposits: implications for Noachian climate scenarios". Geophysical Research Letters 30 (24): E06001. doi:.
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