Školitel: RNDr. Libor Nouzák, Ph.D.
Stav práce: volná
Anotace:
Interplanetary space is not empty but is filled with the solar wind plasma and small objects of various material of micrometer and sub-micrometer size of different shapes called dust. This dust is mostly the product of cometary debris or the collisional cascade of larger objects (e.g., asteroids, micrometeoroids, or space debris). On the other hand, dusty environments around the moons or ringed planets in the interplanetary space can be also populated by ejecta of micrometeoroid bombardment of moon surfaces (e.g., Moon, Europa, etc.) or by volcanic (Io) or thermal activity of the moons themselves (Enceladus). The physical properties of dust particles can be studied in-situ by using both electric field antennas located on the spacecraft and special dust detectors that are designed for each dust environment separately, thus are rarely present. The electric field antennas are a part of the plasma wave subsystem on each spacecraft and the dust is detected as a transient event (spike) in the electric field data. The dust flux is estimated from the abundance of spikes in the data. The ratio of antenna signals provides information about the flux direction, while the size of the signals brings information about the mass of dust particles present in the flux. This approach has been successfully employed on the Parker Solar Probe and Solar Orbiter spacecraft to measure alpha and beta meteroids in the close vicinity of the Sun as well as to determine interplanetary dust flux variation with radial distance from the Sun and solar cycle. We suppose to employ the same detection method for analysis of the Saturn and its rings at different radial distances from Saturn using the Cassini spacecraft. In this case, we plan to involve data from the CDA (Cosmic Dust Analyser) instrument located on board Cassini with motivation to obtain supplementary information about the dust particles detected by the antenna instruments.