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Full-Text Articles in Physics
Dynamical Formation Of Protoplanetesimals, Akbar Whizin
Dynamical Formation Of Protoplanetesimals, Akbar Whizin
Electronic Theses and Dissertations
The seeds of planetesimals that formed in the gaseous protoplanetary disk (PPD) have many barriers to overcome in their growth from millimeter to meter-sized and larger bodies. Centimeter-sized aggregates are weakly bound and self-gravity is almost non-existent so surface forces play a critical role in holding small loosely-bound rubble-piles together. Their orbital motions and effects form disk processes impart relative velocities leading to collisions so understanding the macroscopic disk environment is also necessary. To this end we analyze the dynamics of particles in Saturn's F ring as an analogue to understanding the orbital evolution of proto-planetesimals embedded in a PPD. …
Saturn's Rings: Measuring Particle Size Distributions Using Cassini Uvis Occultation Data, Tracy Becker
Saturn's Rings: Measuring Particle Size Distributions Using Cassini Uvis Occultation Data, Tracy Becker
Electronic Theses and Dissertations
Since its arrival to Saturn in 2004, the Cassini spacecraft has utilized its suite of sophisticated instruments to further our understanding of the Saturnian ring system. We analyze occultation data from Cassini's Ultraviolet Imaging Spectrograph (UVIS) in order to measure the particle size distribution and place limits on the minimum particle sizes in Saturn's rings. Throughout the ring system, particle accretion is countered by collisional and tidal disruption and Keplerian shear. Therefore, the particle size distribution of the rings is continually evolving. The presence of sub-centimeter particles, which have short lifetimes due to these processes, is indicative of ongoing dynamics …