Concentric crater fill (CCF) occurs in the interior of impact craters in midto high latitudes on Mars and is interpreted to have formed by glacial ice flow and debris covering. We use the characteristics and orientation of deposits comprising CCF, the thickness of pedestal deposits in midto high-latitude pedestal craters (Pd), the volumes of the current polar caps, and information about regiona...

A new experimental technique to measure crater growth is presented whereby a high speed video captures profiles of a crater forming after impact obtained using a vertical laser sheet centered on the impact point. Unlike previous so called “quarter-space experiments”, where projectiles were launched along a transparent Plexiglas sheet so that growth of half a crater could be viewed, the use of t...

Introduction: Planetary impacts that occur at the lowest impact angles with respect to horizontal produce craters that are elliptical in planform with the long axis oriented in the downrange direction. Experimental hypervelocity impacts into a strengthless medium suggested that craters should become elliptical for impact angles < ~5 ̊ [1]. Bottke et al. [2] conducted surveys of the crater popula...

Introduction: Recently released, high-resolution images from the Mars Orbiter Camera (MOC) and the Thermal Emission Imaging System (THEMIS) reveal a myriad of intriguing landforms banked along the northern edge of Terby Crater located on the northern rim of Hellas (~28°S, 287°W). Landforms within this crater include north-trending troughs and ridges, a remarkable 2.5 km–thick sequence of expose...

Introduction: The Ries of Nördlingen (diameter: 26 km, age: 14.35 Ma) is the type locality of suevite which is the most characteristic rock type formed in impact craters. Though studied since 1834 [1], the formation and emplacement of suevite in the Ries and in impact craters in general is still enigmatic. As information from suevite can contribute significantly with regard to understanding the...

Fluvial features present around impact craters on Mars can offer insight into the ancient martian climate and its relationship to the impact cratering process. The widespread spatial and temporal distribution of surface ice on Mars suggests that the interaction between impact cratering and surface ice could have been a relatively frequent occurrence. We explore the thermal and melting effects o...

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...

Results by Neukum et al. (2001) and Ivanov (2001) are combined with crater counts to estimate ages of Martian surfaces. These results are combined with studies of Martian meteorites (Nyquist et al., 2001) to establish a rough chronology of Martian history. High crater densities in some areas, together with the existence of a 4.5 Gyr rock from Mars (ALH84001), which was weathered at about 4.0 Gy...