| The Martian crater Eberswalde | |
|---|---|
| Planet | Mars |
| Diameter | 65.3 km |
| Depth | approx 800 m |
| Discoverer | Michael C. Malin and Ken Edgett |
| Eponym | Eberswalde, Brandenburg, Germany |
Eberswalde, formerly known as Holden NE, is a partially buried impact crater in Margaritifer Terra, Mars. Eberswalde Crater lies just to the north of Holden Crater, a large crater that may have been a lake. 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 was one of the final four proposed landing sites for the Mars rover Mars Science Laboratory mission.[2][3]
Landforms in the crater provide strong evidence of the prior existence of flowing water on Mars.
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Several sites in the Margaritifer Sinus quadrangle have been proposed as areas to send NASA's next major Mars rover, the Mars Science Laboratory (MSL). Eberswalde Crater was shortlisted as one of the final four proposed landing sites for the Curiosity rover, part of the MSL mission. It was voted a close second after Gale Crater by a team of scientists.[3]
MRO discovered iron/magnesium smectites here. This mineral requires water to form.[4]
The crater contains a relief inversion, an exhumed delta 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.[5][6]
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.[7][8]
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