Search Publications
The Search for Activity on Dione and Tethys With Cassini VIMS and UVIS
Brown, R. H.; Baines, K. H.; Buratti, B. J. +6 more
During the Cassini mission the Saturnian moons Dione and Tethys showed intriguing and multiple clues suggesting residual geologic activity that might be detectable as an atmosphere, plume, or even heat signature. These clues included an atmospheric aura around Dione, injection of particles into Saturn's magnetosphere, mysterious red streaks on Tet…
First Observation of Transport of Solar Wind Protons Scattered From Magnetic Anomalies Into the Near Lunar Wake: Observations by SARA/Chandrayaan-1
Barabash, Stas; Holmström, Mats; Futaana, Yoshifumi +5 more
We report the first observational evidence for the transport of the solar wind protons scattered from the lunar magnetic anomaly (LMA) into the near wake region from SWIM/Sub-keV Atom Reflecting Analyzer (SARA) aboard Chandrayaan-1. These protons with high angular spread are observed in the near wake region for specific orientations of interplanet…
Limits on Dione's Activity Using Cassini/CIRS Data
Spencer, John R.; Howett, Carly J. A.; Hurford, Terry +2 more
We use nighttime Cassini Composite Infrared Spectrometer (CIRS) data to look for discrete regions of elevated nighttime temperatures indicative of endogenic activity on Dione's surface. This is achieved by producing low latitude and midlatitude (less than 60°) maps of Dione's nighttime surface temperature, derived from 10 to 1,100-cm-1 …
Mysterious Linear Features Across Saturn's Moon Dione
Patthoff, D. Alex; Martin, Emily S.
Our mapping of the wispy terrains on Saturn's moons Dione has revealed unique linear features that are generally long (tens to hundreds of kilometers), narrow (<5 km), and brighter than the surrounding terrains. We refer to these features as linear virgae. Similar features, with a limited distribution, have been observed on Rhea. Wherever linea…
Titan's Variable Ionosphere During the T118 and T119 Cassini Flybys
Wahlund, J. -E.; Edberg, N. J. T.; Andrews, D. J. +6 more
We report on unusual dynamics in Titan's ionosphere as a significant difference in ionospheric electron density is observed between the T118 and T119 Cassini nightside flybys. Two distinct nightside electron density peaks were present during T118, at 1,150 and 1,200 km, and the lowest density ever observed in Titan's ionosphere at altitudes 1,000-…
Enhanced Airglow Signature Observed at Titan in Response to its Fluctuating Magnetospheric Environment
Crary, F.; Wahlund, J. -E.; Esposito, L. W. +1 more
On rare occasions Titan has been observed in the magnetosheath, where the solar wind interferes with the regular magnetic field generated by Saturn. This particular orbital position allows for a deeper investigation of Titan's upper atmosphere response to its highly energetic magnetospheric environment. Although solar extreme ultraviolet radiation…
Intermittent energy dissipation by turbulent reconnection
Eastwood, J. P.; André, M.; Vaivads, A. +5 more
Magnetic reconnection—the process responsible for many explosive phenomena in both nature and laboratory—is efficient at dissipating magnetic energy into particle energy. To date, exactly how this dissipation happens remains unclear, owing to the scarcity of multipoint measurements of the "diffusion region" at the sub-ion scale. Here we report suc…
Methodology to create a new total solar irradiance record: Making a composite out of multiple data records
Schöll, Micha; Dudok de Wit, Thierry; Fröhlich, Claus +1 more
Many observational records critically rely on our ability to merge different (and not necessarily overlapping) observations into a single composite. We provide a novel and fully traceable approach for doing so, which relies on a multiscale maximum likelihood estimator. This approach overcomes the problem of data gaps in a natural way and uses data…
Explaining the rolling-pin distribution of suprathermal electrons behind dipolarization fronts
Cao, J. B.; Xu, Y.; Fu, H. S. +2 more
The rolling-pin distribution of suprathermal electrons (40-200 keV), showing electron pitch angles primarily at 0°, 90°, and 180°, has recently been reported behind dipolarization fronts (DFs) both in observations and simulations. The formation of such type of distribution, however, has been unclear so far. In this study, we present an observation…
Response of Jupiter's auroras to conditions in the interplanetary medium as measured by the Hubble Space Telescope and Juno
Wilson, R. J.; Kurth, W. S.; McComas, D. J. +24 more
We present the first comparison of Jupiter's auroral morphology with an extended, continuous, and complete set of near-Jupiter interplanetary data, revealing the response of Jupiter's auroras to the interplanetary conditions. We show that for ∼1-3 days following compression region onset, the planet's main emission brightened. A duskside poleward r…