2011年1月1日 · Ejecta were collected in bins at various distances from the impact. The observed nearly-90° ejection angle and the fall-distance to the chamber floor were used to calculate the ejection velocity of material in the collection bins. The …

Martian ejecta blankets often indicate extensive ground-hugging flow away from the crater, most likely due to groundwater or melted ice in the ejecta. Extensive, runout ejecta flows exist on Venus, thought to be due to entrained atmosphere or an enhanced fraction of impact melt in the ejecta (due to the high surface temperatures of Venusian ...

The rock avalanche/ ejecta (RAEJ) documented by Crosta et al. (2018a, b) represent peculiar types of landslides that can be found on Mars but are unknown on Earth (Fig. 14). These landslides initially acquired momentum by asteroid impact and started as impact ejecta or as destabilization of slope masses directly neighboring the impact crater ...

2024年9月1日 · Distal ejecta make up about 10 % of the total ejecta and consist primarily of material that is highly shock metamorphosed, melted or vaporized and can be found in ejecta blankets from impact events throughout Earth’s geologic history (e.g., Glass and Simonson, 2013). During this process, ejected (ballistic) melt rapidly cools to form non ...

2019年3月1日 · As an example, Fig. 3 shows the ejecta velocity histogram with cumulative size distribution for a Cu projectile impacting on a sandstone target. A luminescent transient plasma plume followed by a steepening ejecta cone and completed by the detachment of spall fragments characterizes the typical evolution of ejecta [12]. The high-speed camera ...

2022年3月1日 · The amount by which crater ejecta enhances asteroid deflection—that is, the momentum of the crater ejecta that escapes the gravitational attraction of the target body divided by the impactor momentum (β − 1)—has been found to vary significantly depending on the target asteroid’s properties, composition and structure (e.g., Jutzi and ...

2024年5月1日 · Ejecta with Stokes number S t k ≪ 1 is expected to follow the flow, whereas ejecta with S t k ≫ 1 has a motion independent of the surrounding flow field. The Stokes number for the mean size of the ejecta and the range of velocities is S t k ≈ 5500, which implies that the ejecta would follow a ballistic path given an initial momentum impulse.

2014年5月1日 · 1. Introduction. Martian impact craters often exhibit unique ejecta morphologies relative to ballistically-dominated ejecta observed in lunar and mercurian impact craters (Carr et al., 1977, Schultz and Gault, 1979): martian lobate ejecta deposits frequently have distinctive ejecta deposit boundaries rather than an ejecta deposit of gradational thickness, and appear …

2011年10月15日 · Ejecta deposits very poorly exposed and eroded in close proximity to the crater rim. In the Tyasmin River valley ~ 6–8 km outside the crater rim, low shock, melt-free “monomict” breccias are overlain by polymict breccias (Gurov et al., 2003). Both breccias comprise crystalline rocks; polymict breccias contain more highly shocked material.

2015年1月1日 · When the ejecta length of all experimental results was normalized by projectile diameter on the horizontal axis as shown in Fig. 4(c), the cumulative number distributions were divided into three groups according to the impact velocity. The cumulative number of ejecta length on the vertical axis increased with increasing impact velocity.