Date: Monday 30-Oct-2023
Time: 11:15 am-12:15 pm
Location: Zoom (contact host Jacob Kloos for link)
Speaker: Stavro Ivanovski (INAF)
Title: Dust dynamics in expanding flow in different small bodies environments
Abstract: I will review the dust dynamics studies in two small bodies environments – one in the vicinity of a comet 67P and another one of the vicinities of Dimorphos after the impact of the DART spacecraft. The focus will be the similarity of the rotational motion of dust particles in the inner atmospheres of comets and whether we can derive such similarity in the ejecta plume dynamics after the impact on asteroid.
In-situ measurements of individual dust grain parameters in the immediate vicinity of a cometary nucleus are being carried by the Rosetta spacecraft at comet 67P/Churyumov-Gerasimenko. For interpretation of these observational data, a model of dust grain motion as realistic as possible is requested. In particular, the results of Stardust mission and analysis of samples of interplanetary dust have shown that these particles are highly non-spherical. In many cases precise simulations of non-spherical grain’s dynamics is either impossible or computationally too expensive. I will present the derivation of scaling laws of rotational motion applicable for any shape of particles, using a set of universal, dimensionless parameters characterizing the dust motion in the inner cometary coma. The scaling relations for translational and rotational motion of dust grains in a cometary environment are proposed.
In the second part of my talk, I will present latest results on advancements on the reconstruction of the dust dynamics of the plume formed after the NASA’s Double Asteroid Redirection Test (DART) impact, the first space mission that successfully demonstrated the kinetic impactor technique more than a year ago. ASI’s Light Italian Cubesat for Imaging of Asteroids (LICIACube) was the first Cubesat to image this plume. The DART impact into Dimorphos caused ejecta plume propagation with high velocity and very filamentary structure, composed of dust particles from μm to cm sizes in size. To estimate the size distribution and velocity distribution of the plume in close vicinity to Dimorphos, captured in the LICIACube images is still unanswered question. A 3D+t model was used to compute single particle trajectories, the dust rotational frequencies and velocity as well as the particle orientation at any time and distance. The role of the fragmentation of the particles has been addressed for reconstruction of the plume structure.
If you have any questions, contact the PALS hosts: Jacob Kloos (small bodies) and Matt Nixon (exoplanets).
SPECIAL ACCOMMODATIONS:Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.
