Introduction: Crater ejecta launched from the surface of small, rapidly-rotating, and highly-elongated and irregularly-shaped bodies are subjected to a complex dynamical process. Dynamical models [1,2] of reaccretion of impact ejecta on asteroids provide important tools for a detailed investigation of the distribution of blocks and finer regolith across Eros’ surface as revealed by the NEAR MSI...

a r t i c l e i n f o Amazonian non-polar ice deposits on Mars record periods and events when the climate differed substantially from that of today. Particularly evident are examples of ice-rich deposits in the martian mid-latitudes (lobate debris aprons, lineated valley fill, and concentric crater fill). Uncertain, however, is the amount of ice remaining in these deposits today, and the thickn...

Introduction: In the Noachian, Mars’ crust was deeply affected by impact crater gardening [1], and subsequent hydrothermal alteration. While water was present in the Martian crust [2,3], frequent impacts [4,5] provided prominent heat sources that drove hydrothermal systems. Those systems were scattered randomly over the planet’s surface and variable in size, but generally spanned the diameter o...

available online at http://meteoritics.org 1675 © The Meteoritical Society, 2006. Printed in USA. Breccia dikes and crater-related faults in impact craters on Mars: Erosion and exposure on the floor of a crater 75 km in diameter at the dichotomy boundary James W. HEAD* and John F. MUSTARD Department of Geological Sciences, Brown University, Providence, Rhode Island 02912, USA *Corresponding aut...

Introduction: In simple impact craters like Barringer Meteorite Crater (aka Meteor Crater), very little molten material was generated. There are no detectable melt ponds within the breccia lens or any significant melt pools on the crater walls or in the ejecta blanket. There was either an insufficient volume of melt produced by the impact event and/or it was too finely disseminated, possibly be...

Introduction: It has long been a matter of debate whether there exist any characteristic features in crater morphology diagnostic for oblique impacts [e.g. 1,2]. The vast majority of impact craters are almost circular in plain view, although it is well known that most impacts occur at an oblique angle of incidence [3]. Impact events may be approximated as a stationary point source of energy and...

Small craters (less than one kilometer diameter) can be primary craters produced by impact of interplanetary debris, or they can be secondary craters produced by fallback of high-velocity ejecta blocks from much larger but infrequent primary impacts. The prevalent assumption over recent decades has been that primaries are most abundant, so most small craters are independent random events and ca...

Introduction: Scaling relations derived from laboratory experiments and dimensional analysis [1] provide first-order estimates for the diameters of objects responsible for craters on the planets. At basin scales, however, the final crater rim may not be preserved due to rim collapse. Assumptions about impactor speed, angle, and density further preclude a unique determinations. As a result, the ...

[1] Impact basin formation is a fundamental process in the evolution of the Moon and records the history of impactors in the early solar system. In order to assess the stratigraphy, sequence, and ages of impact basins and the impactor population as a function of time, we have used topography from the Lunar Orbiter Laser Altimeter (LOLA) on the Lunar Reconnaissance Orbiter (LRO) to measure the s...

Upon impact of a meteorite with a planetary surface the resulting shock wave both 'processes' the material in the vicinity of the impact and sets a larger volume of material than was subjected to high pressure into motion. Most of the volume which is excavated by the impact leaves the crater after the shock wave has decayed. The kinetic energy which has been deposited in the planetary surface i...