Related papers: The Atomic Hydrogen Cloud in the Saturnian System
Thermochemical modeling and shock-tube experiments show that shocks applied to N$_2$/CH$_4$ gas mixtures can synthesize organic molecules. Sufficiently large, hypersonic meteoroids entering the atmosphere of Saturn's moon Titan should…
The majority of hydrogen in the interstellar medium (ISM) is in atomic form. The transition from atoms to molecules and, in particular, the formation of the H$_2$ molecule, is a key step in cosmic structure formation en route to stars.…
The detection of outgassing water vapor from Enceladus is one of the great breakthroughs of the Cassini mission. The fate of this water once ionized has been widely studied; here we investigate the effects of purely neutral-neutral…
During the accretion of Titan, impact heating may have been sufficient to allow the global melting of water ice and the release of volatile compounds, mainly constituted of CO2, CH4 and NH3. The duration and efficiency of exchange between…
Our analysis of Cassini/VIMS near-infrared spectra of Saturn's Great Storm of 2010-2011 reveals a multi-component aerosol composition comprised primarily of ammonia ice, with a significant component of water ice. The most likely third…
Observations of spiral galaxies show a strong linear correlation between the ratio of molecular to atomic hydrogen surface density R_mol and midplane pressure. To explain this, we simulate three-dimensional, magnetized turbulence, including…
We study the seasonal evolution of Titan's lower stratosphere (around 15~mbar) in order to better understand the atmospheric dynamics and chemistry in this part of the atmosphere. We analysed Cassini/CIRS far-IR observations from 2006 to…
Titan has a climate system with similarities to Earth, including the presence of a thick atmosphere made up of several atmospheric layers. As on Earth, Titan's climate is influenced by several factors: the gaseous species making up the…
Saturn's largest satellite, Titan, has a thick atmosphere dominated by nitrogen and methane. The dense orange-brown smog hiding the satellite's surface is produced by photochemical reactions of methane, nitrogen and their dissociation…
Previous investigations have employed more than 100 close observations of Titan by the Cassini orbiter to elucidate connections between the production and distribution of Titan's vast, organic-rich chemical inventory and its atmospheric…
Tidal interactions between Saturn and its satellites play a crucial role in both the orbital migration of the satellites and the heating of their interiors. Therefore constraining the tidal dissipation of Saturn (here the ratio k2/Q) opens…
We apply a 1D upper atmosphere model to study thermal escape of nitrogen over Titan's history. Significant thermal escape should have occurred very early for solar EUV fluxes 100 to 400 times higher than today with escape rates as high as…
The fluid dynamics in planet Saturn gives rise to alternating east-west jet streams, large cyclonic and anticyclonic vortices, and a dipole-dominant magnetic field which is highly axisymmetric about the planetary rotation axis. Modelling…
We investigate the effects of varying Saturn's orbit on the atmospheric circulation and surface methane distribution of Titan. Using a new general circulation model of Titan's atmosphere, we simulate its climate under four characteristic…
During the Grand Finale stage of the Cassini mission, organic-rich ring material was discovered to be flowing into Saturn's equatorial upper atmosphere at a surprisingly large rate. Through a series of photochemical models, we have examined…
A large drift in the rotation rate of Titan observed by Cassini provided the first evidence of a subsurface ocean isolating the massive core from the icy crust. Seasonal exchange of angular momentum between the surface and atmosphere…
Water vapour is delivered to Saturn's stratosphere by Enceladus' plumes and subsequent diffusion in the planet system. It is expected to condense into a haze in the middle stratosphere. The hot stratospheric vortex (the `beacon') that…
The weather layers of the gas giant planets, Jupiter and Saturn, comprise the shallow atmospheric layers that are influenced energetically by a combination of incoming solar radiation and localised latent heating of condensates, as well as…
The D/H enrichment observed in Saturn's satellite Enceladus is remarkably similar to the values observed in the nearly-isotropic comets. Given the predicted strong variation of D/H with heliocentric distance in the solar nebula, this…
We present results of an investigation into the formation of nitrogen-bearing molecules in the atmosphere of Titan. We extend a previous model (Li et al. 2015, 2016) to cover the region below the tropopause, so the new model treats the…