ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Astrophysics  (2)
  • Geochemistry, Geophysics, Planetary Science  (1)
  • 2015-2019  (3)
  • 1
    facet.materialart.
    Unknown
    In situ measurements of Saturns ionosphere show that it is dynamic and interacts with the rings (2018)
    American Association for the Advancement of Science (AAAS)
    In: Science
    Details
    Publication Date: 2018-01-05
    Description: The ionized upper layer of Saturn’s atmosphere, its ionosphere, provides a closure of currents mediated by the magnetic field to other electrically charged regions (for example, rings) and hosts ion-molecule chemistry. In 2017, the Cassini spacecraft passed inside the planet’s rings, allowing in situ measurements of the ionosphere. The Radio and Plasma Wave Science instrument detected a cold, dense, and dynamic ionosphere at Saturn that interacts with the rings. Plasma densities reached up to 1000 cubic centimeters, and electron temperatures were below 1160 kelvin near closest approach. The density varied between orbits by up to two orders of magnitude. Saturn’s A- and B-rings cast a shadow on the planet that reduced ionization in the upper atmosphere, causing a north-south asymmetry.
    Keywords: Geochemistry, Geophysics, Planetary Science
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Computer Science , Medicine , Natural Sciences in General , Physics
    Published by American Association for the Advancement of Science (AAAS)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 2
    facet.materialart.
    Unknown
    Ion Trapping by Dust Grains: Simulation Applications to the Enceladus Plume (2017)
    In:  CASI
    Details
    Publication Date: 2019-07-13
    Description: Using a particleincell electrostatic simulation, we examine the conditions that allow lowenergy ions, like those produced in the Enceladus plume, to be attracted and trapped within the sheaths of negatively charged dust grains. The conventional wisdom is that all new ions produced in the Enceladus plume are free to get picked up (i.e., accelerated by the local E field to then undergo vB acceleration). However, we suggest herein that the presence of submicroncharged dust in the plume impedes this pickup process since the local grain electric field greatly exceeds the corotation E fields. The simulations demonstrate that cold ions will tend to accelerate toward the negatively charged grains and become part of the ion plasma sheath. These trapped ions will move with the grains, exiting the plume region at the dust speed. We suggest that Cassini's Langmuir probe is measuring the entire ion population (free and trapped ions), while the Cassini magnetometer detects the magnetic perturbations associated with pickup currents from the smaller population of free ions, with this distinction possibly reconciling the ongoing debate in the literature on the ion density in the plume.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN40343 , Journal of Geophysical Research: Planets (ISSN 2169-9097) (e-ISSN 2169-9100); 122; 4; 729-743
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    A Persistent, Large-Scale, and Ordered Electrodynamic Connection Between Saturn and Its Main Rings (2019)
    In:  Other Sources
    Details
    Publication Date: 2019-09-28
    Description: Auroral hiss emissions are ubiquitous in planetary magnetospheres, particularly in regions where electric current systems are present. They are generally diagnostic of electrodynamic coupling between conductive bodies, thus making auroral and moon-connected magnetic field lines prime locations for their detection. However, the role of Saturn's rings as a dynamic conductive body has been elusive and of great interest to the community. Cassini's Grand Finale orbits afforded a unique opportunity to directly sample magnetic field lines connected to the main rings. Here we provide strong evidence for the persistent and organized presence of auroral hiss demonstrably associated with the main rings. This is in contrast to recent observations suggesting that Saturn's rings may be barriers to field-aligned currents. Our results provide a new view of Saturn's rings as a dynamic system that is in continuous and ordered electrodynamic coupling with the planet.
    Keywords: Astrophysics
    Type: GSFC-E-DAA-TN73239 , Geophysical Research Letters (ISSN 0094-8276) (e-ISSN 1944-8007); 46; 13; 7166-7172
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...