The NASA-APL DART (Double Asteroid Redirection Test) spacecraft will impact at a speed of about 6 km/s on Dimorphos, the secondary member of an S-type near-Earth binary asteroid of the Apollo-Amor group whose main body is (65803) Didymos as a test of the kinetic impactor deflection method against possibly hazardous Near Earth Asteroids.. The impact, crater formation and debris ejection will be observed in real time from the Italian Space Agency (ASI) probe LICIACube, a cubesat released ten days before the impact, while ground observatories will measure, in the following weeks and months, the change in the rotation period of Dimorphos around Didymos. To exploit the wealth of data obtained and to understand the physics of the whole impact experiment it is of paramount importance to properly model the dynamics of the binary system pre- and post-impact and the dynamics of the particles ejected from the impact crater. A model was developed to simulate the evolution of the ejecta particles created during the impact in order first to interpret the LICIACube images and then to test the survival of particles on long interval of times which might be detected by the Hera mission, either as individual bodies or as part of rings, when it will reach the binary system four years after DART. The dynamical evolution of the particles is simulated over different time scales to highlight the most important perturbations and their relative importance. The ejecta dynamics turn out to be highly chaotic over relatively short time scales due to repeated close encounters with the two asteroids. However, we find that some ejecta survive in the binary orbital environment for time scales comparable to the Hera arrival time. The effects of the particles re-impacting against either one of the components is also analyzed to estimate the amount of momentum transfer to the target bodies and to assess if any detectable change in the spin rate of Didymos can by hypothesized. The effects of the secondary impacts on the possible creation of a dynamic dusty environment within the binary system is investigated too.
EJECTA DYNAMICS FROM THE DART IMPACT AGAINST DIMORPHOS
Rossi Alessandro;
2022
Abstract
The NASA-APL DART (Double Asteroid Redirection Test) spacecraft will impact at a speed of about 6 km/s on Dimorphos, the secondary member of an S-type near-Earth binary asteroid of the Apollo-Amor group whose main body is (65803) Didymos as a test of the kinetic impactor deflection method against possibly hazardous Near Earth Asteroids.. The impact, crater formation and debris ejection will be observed in real time from the Italian Space Agency (ASI) probe LICIACube, a cubesat released ten days before the impact, while ground observatories will measure, in the following weeks and months, the change in the rotation period of Dimorphos around Didymos. To exploit the wealth of data obtained and to understand the physics of the whole impact experiment it is of paramount importance to properly model the dynamics of the binary system pre- and post-impact and the dynamics of the particles ejected from the impact crater. A model was developed to simulate the evolution of the ejecta particles created during the impact in order first to interpret the LICIACube images and then to test the survival of particles on long interval of times which might be detected by the Hera mission, either as individual bodies or as part of rings, when it will reach the binary system four years after DART. The dynamical evolution of the particles is simulated over different time scales to highlight the most important perturbations and their relative importance. The ejecta dynamics turn out to be highly chaotic over relatively short time scales due to repeated close encounters with the two asteroids. However, we find that some ejecta survive in the binary orbital environment for time scales comparable to the Hera arrival time. The effects of the particles re-impacting against either one of the components is also analyzed to estimate the amount of momentum transfer to the target bodies and to assess if any detectable change in the spin rate of Didymos can by hypothesized. The effects of the secondary impacts on the possible creation of a dynamic dusty environment within the binary system is investigated too.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
