Impacts on planetary bodies can lead to both prompt secondary craters and projectiles that reimpact the target body or nearby companions after an extended period, producing so-called ‘‘sesquinary” craters. Here we examine sesquinary cratering on the moons of Mars. We model the impact that formed Voltaire, the largest crater on the surface of Deimos, and explore the orbital evolution of resultin...

the purpose of velocity analysis is to extract the normal moveout velocity as a function of the zero-offset travel time at selected cdp locations along the seismic line. since results of velocity analysis depend on coherency estimator, an estimator that provides a high velocity resolution is essential. even though the conventional semblance method which is the most popular coherency estimator (...

Introduction: The velocity distribution of impact ejecta from regolith-like target has been investigated in laboratory for nearly three decades. For the case of vertical impact, the ejecta velocity distribution is determined experimentally and given by a power-law with an exponent of –1.22 [1]. There is an upper limit to the ejecta velocity (Hartmann cutoff velocity) that depends on impact velo...

Extremely high velocity (EHV) wings, with full widths of 72 to 140 km s, are seen on the CO J = 3→2 lines toward W3 IRS 5, GL 490, NGC 2071, W28 A2 (G05.89–0.39), GL 2591, S140, and Cepheus A. Observations of CO and CO J = 3→2 and J = 2→1 lines indicate that optical depth generally decreases with increasing velocity separation from the ambient cloud velocity. Maps of the extremely high velocity...

We summarize the observed properties of the CHVC population, which provide strong evidence for source distances in the range 200– 1000 kpc. At these distances, the population corresponds to strongly dark-matter dominated sub-dwarf galaxies still accreting onto the more massive Local Group systems. Recent searches for faint associated stellar populations have revealed red-giant candidates for wh...

Rear impact collisions are mostly low severity, but carry a very high societal cost due to reported symptoms of whiplash and related soft tissue injuries. Given the difficulty in physiological measurement of damage in whiplash patients, there is a significant need to assess rear impact severity on the basis of vehicle damage. This paper presents fundamental impact equations on the basis of an e...

Understanding high-velocity microparticle impact is essential for many fields, from space exploration to medicine and biology. Investigations of microscale impact have hitherto been limited to post-mortem analysis of impacted specimens, which does not provide direct information on the impact dynamics. Here we report real-time multi-frame imaging studies of the impact of 7 μm diameter glass sphe...

Introduction: Many laser experiments have been done to simulate hypervelocity impact vaporization [e.g., 15]. Laser simulation has a number of advantages. It can create high-temperature plumes with high repeatability and a high repetition cycle at a relatively low cost. Furthermore, because laser light can penetrate through a glass window (if chosen properly), the target material and vaporizati...