![]() ![]() 2020), where the bulk density of the projectile 1.740 g/cm 3 is calculated by assuming that the projectile is a sphere with a diameter of 13 cm and a mass of 2 kg. An important outcome is that the size of the artificial crater produced on Ryugu is well scaled by a conventional scaling law in the gravity regime when the bulk density is simply set as the projectile density in the scaling law (Arakawa et al. This SCI instrument launched a copper projectile with a mass of 2 kg, in the shape of a spherical shell-a hollow ball with a thickness of approximately 5 mm and a diameter of 13 cm. Graphical abstractĪn impact experiment was performed on the surface of the C-type asteroid 162173 Ryugu using an instrument called the Small Carry-on Impactor (SCI), carried by JAXA spacecraft Hayabusa2 (Arakawa et al. Thus, we conclude that the size of the craters formed by the impact of projectiles with different shape and interior structure can be scaled using a conventional scaling law in the strength regime, using bulk density as projectile density. This is consistent with the experimental results. Results show that the distributions of the maximum (peak) pressure experienced and particle velocity in the targets were similar regardless of projectile shape and interior structure, implying that the dimensions of the final craters were almost identical. The numerical code iSALE was used to simulate the impact of projectiles of various shapes and interior structure with similar bulk densities. Using the bulk density of the projectile, the surface diameter and depth for basalt and the pit diameter and depth for porous gypsum were scaled using the pi-scaling law for crater formation in the strength regime. The surface diameter, inner (pit) diameter, and depth of the craters on basalt and porous gypsum targets were measured. However, these data are in conflict with trajectories inferred from the analysis of infrasound signals.Experiments on crater formation in the strength regime were conducted using projectiles of various shapes with an aspect ratio of ~ 1, including both solid and hollow interiors. Aerodynamic and crater modeling are consistent with field data and our microscopic inspection. This scenario results in a strong meteoroid deceleration, a deflection of the trajectory to a steeper impact angle (40–60 °), and an impact velocity of 350–600 ms−1, which is insufficient to produce a shock wave and significant shock effects in target minerals. By modeling the atmospheric traverse we demonstrate that low cosmic velocities (12–14 kms−1) and shallow entry angles (<20 °) are prerequisites to keep aerodynamic stresses low (<10 MPa) and thus to prevent fragmentation of stony meteoroids with standard strength properties. Depending on the strength properties of the target, the impact energies range between approximately 100–1000 MJ (0.024–0.24 t TNT). To constrain the possible range of impact parameters we carried out numerical models of crater formation with the iSALE hydrocode in two and three dimensions. ![]() We present results of a detailed geologic survey of the crater and its ejecta. The Carancas cratering event, however, demonstrates that meter-sized stony meteoroids indeed can survive the atmospheric passage under specific circumstances. The small fragments that result from a breakup rain down at terminal velocity and are not capable of producing impact craters. Fragmentation occurs if the strength of the meteoroid is less than the aerodynamic stresses that occur in flight. The impact violated the hitherto existing view that stony meteorites below a size of 100 m undergo major disruption and deceleration during their passage through the atmosphere and are not capable of producing craters. It is the smallest, youngest, and one of two eye-witnessed impact crater events on Earth. An H4–5 chondrite struck the Earth south of Lake Titicaca in Peru on September 15, 2007, and formed a crater 14.2 m across. Abstract- The recent Carancas meteorite impact event caused a worldwide sensation.
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