Dust release from cold ring particles as a mechanism of spoke formation in Saturn's rings
Fuente:
arXiv
Guardado en:
| Autores principales: | , , |
|---|---|
| Formato: | Preprint |
| Publicado: |
2022
|
| Materias: | |
| Acceso en línea: | |
| Etiquetas: |
Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
|
| _version_ | 1866914702773190656 |
|---|---|
| author | Hirata, Naoyuki Kimura, Hiroshi Ohtsukia, Keiji |
| author_facet | Hirata, Naoyuki Kimura, Hiroshi Ohtsukia, Keiji |
| contents | Spokes in Saturn's rings are radially-extended structures consisting of dust grains. Although spacecraft and space telescope observations have revealed various detailed features of the spokes and their time variation, their formation mechanism is still under debate. Previous models examined charging mechanisms to attempt at explaining dust release from cm-sized ring particles; however, the attempt has been unsuccessful, because the electrostatic force caused by such charging mechanisms is much weaker than the cohesive force acting on dust grains at ordinary conditions in the ring environment. Here we propose a novel model for the formation of the spokes, where the temperature dependence of cohesion plays an essential role. Ring particles with a temperature below 60K adsorb an O2 ring atmosphere, which facilitates release of dust grains from them by a reduction in the cohesive force between the grains and the particles on the morning ansa. Then, intense electrostatic forces sufficient to overcome the cohesive force are generated on the surface of ring particles and the released dust grains form the structure of spokes. Our model explains observational features of the spokes including their longitudinal location, lifetime, radial expansion velocity, and seasonality. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2205_07008 |
| institution | arXiv |
| publishDate | 2022 |
| record_format | arxiv |
| spellingShingle | Dust release from cold ring particles as a mechanism of spoke formation in Saturn's rings Hirata, Naoyuki Kimura, Hiroshi Ohtsukia, Keiji Earth and Planetary Astrophysics Spokes in Saturn's rings are radially-extended structures consisting of dust grains. Although spacecraft and space telescope observations have revealed various detailed features of the spokes and their time variation, their formation mechanism is still under debate. Previous models examined charging mechanisms to attempt at explaining dust release from cm-sized ring particles; however, the attempt has been unsuccessful, because the electrostatic force caused by such charging mechanisms is much weaker than the cohesive force acting on dust grains at ordinary conditions in the ring environment. Here we propose a novel model for the formation of the spokes, where the temperature dependence of cohesion plays an essential role. Ring particles with a temperature below 60K adsorb an O2 ring atmosphere, which facilitates release of dust grains from them by a reduction in the cohesive force between the grains and the particles on the morning ansa. Then, intense electrostatic forces sufficient to overcome the cohesive force are generated on the surface of ring particles and the released dust grains form the structure of spokes. Our model explains observational features of the spokes including their longitudinal location, lifetime, radial expansion velocity, and seasonality. |
| title | Dust release from cold ring particles as a mechanism of spoke formation in Saturn's rings |
| topic | Earth and Planetary Astrophysics |
| url | https://arxiv.org/abs/2205.07008 |