Search Publications
Magnetic signatures of a tenuous atmosphere at Dione
Dougherty, Michele K.; Saur, Joachim; Simon, Sven +2 more
We present Cassini magnetic field observations from the only two close flybys (16DI and 129DI) of Saturn's icy satellite Dione which have been carried out so far. Data from 16DI show a weak field perturbation in the upstream region, indicative of a tenuous atmosphere around the satellite. By applying an analytical model of the perturbations caused…
Resolution of the lunar hydrogen enigma
Hodges, R. R.
The recent discovery, by instruments on the IBEX and Chandrayaan-1 spacecraft, of significant fluxes of energetic hydrogen atoms escaping from the moon suggests that there are flaws in the common wisdom regarding the interaction of solar wind with lunar regolith that have prevailed in attempts to explain the failure of the Apollo 17 far-ultraviole…
Hot electrons as tracers of large-scale structure of magnetotail current sheets
Petrukovich, A. A.; Zelenyi, L. M.; Nakamura, R. +1 more
This paper is devoted to the investigation of the vertical electron temperature distribution in thin currents sheets of the Earth magnetotail. The dependence of electron temperature on magnetic field Te(Bx) is examined for 62 thin currents sheet crossings by the Cluster spacecraft. The profiles Te(Bx) ar…
Auroral hiss, electron beams and standing Alfvén wave currents near Saturn's moon Enceladus
Schippers, P.; Gurnett, D. A.; Persoon, A. M. +8 more
Observations from the Cassini spacecraft have shown that Saturn's small icy moon Enceladus ejects a plume of water vapor and small ice particles into Saturn's rapidly co-rotating magnetosphere. In this paper we show that the interaction of the moon with the magnetospheric plasma produces a number of electrodynamics effects that are remarkably simi…
The search for Titan lightning radio emissions
Gurnett, D. A.; Fischer, G.
We report on the non-detection of radio emissions indicative of Titan lightning by the Cassini RPWS (Radio and Plasma Wave Science) instrument. A previous study by Fischer et al. (2007) investigated the first 35 Titan flybys, and here we continue our search until the end of Cassini's equinox mission. No bursts that would clearly indicate the exist…
Saturn's equatorial oscillation: Evidence of descending thermal structure from Cassini radio occultations
French, R. G.; Flasar, F. M.; Rappaport, N. J. +7 more
A series of near-equatorial radio occultations of Cassini by Saturn occurred in 2005 and again in 2009-2010. Comparison of the temperature-pressure profiles obtained from the two sets of occultations shows evidence of a descending pattern in the stratosphere that is similar to those associated with equatorial oscillations in Earth's middle atmosph…
Supercorotating return flow from reconnection in Saturn's magnetotail
Coates, A. J.; Dougherty, M. K.; Thomsen, M. F. +4 more
Detecting plasma dynamics in Saturn's magnetosphere is essential for understanding energy flow through the system. It has been proposed that both the Dungey and Vasyliunas cycles operate at Saturn, and the competition between these cycles has been debated. We examine data taken by the Cassini spacecraft in Saturn's post-dawn magnetosphere, ∼17.5 S…
The global energy balance of Titan
West, Robert A.; Baines, Kevin H.; Nixon, Conor A. +12 more
The global energy budget of planets and their moons is a critical factor to influence the climate change on these objects. Here we report the first measurement of the global emitted power of Titan. Long-term (2004-2010) observations conducted by the Composite Infrared Spectrometer (CIRS) onboard Cassini reveal that the total emitted power by Titan…
Jet front-driven mirror modes and shocklets in the near-Earth flow-braking region
Retinò, Alessandro; Khotyaintsev, Yuri; Vaivads, Andris +3 more
We investigate the small-scale structure of jet fronts through a case study of multi-spacecraft Cluster observations in the near-Earth flow-braking region at ∼-10 RE. We find that the interaction between the earthward moving fast plasma jet and the high-β ambient plasma in the plasma sheet results in magnetic pileup and compression ahea…
On accelerated magnetosheath flows under northward IMF
Farrugia, C. J.; Erkaev, N. V.; Harris, B. +1 more
We study the acceleration of magnetosheath plasma using a semi-analytical magnetic string approach for a range of solar wind Alfvén Mach numbers, MA, between 2 and 20. We work with an IMF vector perpendicular to the solar wind velocity, Vsw, and pointing north. We do not invoke magnetic reconnection. Our results indicate that…