On September 30, 2022, NASA's Double Asteroid Redirection Test (DART) mission will be the first space mission demonstrating the kinetic impactor method for planetary defense. DART will impact Didy- mos B (a 164±18 m secondary of asteroid (65803) Did- ymos) with its mass of 650 kg and at a speed of 6.6 km/s. Such impact is expected to change the secondary orbital period by about 10 minutes. DART will carry as a piggyback the Light Italian Cubesat for Imaging of Asteroids (LICIACube) which will be released from DART ten days before the impact. LICIACube will pro- vide evidence of the impact and will take multiple im- ages of the target up to a distance of ~55 km from the target. The LICIACube narrow and wide angle cameras - LEIA (LICIACube Explorer Imaging for Asteroid) and LUKE (LICIACube Unit Key Explorer), respec- tively - will capture the post-impact processes coming from in situ events, such as the newly formed crater, the expanding ejecta and the dynamics of its plume. In par- ticular, the measurement of the motion of the slow (<5 m/s) ejecta in the plume will be feasible with LICI- ACube, thus allowing description of its structure and the evolution of the dust size and velocity distribution. In this work, we study the motion of the plume evolution in terms of dust numerical simulations. To accomplish this, we modified the non-spherical dust model and applied it to an asteroid impact scenario using analytical expressions to estimate the initial velocity and mass of ejecta. As input we used the ejecta impact properties (ejecta mass, velocity, launch position distribution, orientation) constrained with iSALE numerical simulations. We discuss the influence of the non-sphericity of the particles on the dynamical properties of the plume, such as the velocity and dust spatial distribution, and address the optical thickness not only in terms of particle size distribution but also as a function of particle shape and orientation.
Modelling dust distribution in the ejecta plume from nonspherical dust dynamics perspectives in support of the LICIACube and DART missions
A Rossi;
2020
Abstract
On September 30, 2022, NASA's Double Asteroid Redirection Test (DART) mission will be the first space mission demonstrating the kinetic impactor method for planetary defense. DART will impact Didy- mos B (a 164±18 m secondary of asteroid (65803) Did- ymos) with its mass of 650 kg and at a speed of 6.6 km/s. Such impact is expected to change the secondary orbital period by about 10 minutes. DART will carry as a piggyback the Light Italian Cubesat for Imaging of Asteroids (LICIACube) which will be released from DART ten days before the impact. LICIACube will pro- vide evidence of the impact and will take multiple im- ages of the target up to a distance of ~55 km from the target. The LICIACube narrow and wide angle cameras - LEIA (LICIACube Explorer Imaging for Asteroid) and LUKE (LICIACube Unit Key Explorer), respec- tively - will capture the post-impact processes coming from in situ events, such as the newly formed crater, the expanding ejecta and the dynamics of its plume. In par- ticular, the measurement of the motion of the slow (<5 m/s) ejecta in the plume will be feasible with LICI- ACube, thus allowing description of its structure and the evolution of the dust size and velocity distribution. In this work, we study the motion of the plume evolution in terms of dust numerical simulations. To accomplish this, we modified the non-spherical dust model and applied it to an asteroid impact scenario using analytical expressions to estimate the initial velocity and mass of ejecta. As input we used the ejecta impact properties (ejecta mass, velocity, launch position distribution, orientation) constrained with iSALE numerical simulations. We discuss the influence of the non-sphericity of the particles on the dynamical properties of the plume, such as the velocity and dust spatial distribution, and address the optical thickness not only in terms of particle size distribution but also as a function of particle shape and orientation.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
