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 …

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.

2021年9月15日 · Continuous ejecta deposits around Martian layered ejecta craters larger than about a kilometer in diameter typically exhibit features such as lobate outlines, and extensive sets of radial grooves and ridges that suggest substantial flow of their ejecta during its emplacement (e.g., see Carr et al., 1977; Strom et al., 1992; Barlow et al., 2000; Robbins and Hynek, 2012).

2024年9月1日 · Impact cratering is an important geological process on Earth. This review summarizes the state of knowledge of the Precambrian (Hadean, Archean, and P…

The size of ejecta that penetrated the foil targets at a velocity lower than the assumed values would have been underestimated, as the ratio of the hole size to ejecta size increases with velocity. Table 2 shows the constant values we determined for Eq. (1) for each ejecta velocity, while Fig. 3 a illustrates the empirical relationship ...

Therefore, the forward ejecta ratio varies across different materials and impact conditions, making it an effective metric for evaluating forward ejecta. Table 6 presents the mass of the recovered ejecta and difference in target mass before and after impact measured in the impact experiments, and the corresponding numerical results.

2014年5月1日 · 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 to have been fluidized during their ...

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.