相关论文: A primordial origin for the atmospheric methane of…
The Saturn System has been studied in detail by the Cassini-Huygens Mission. A major thrust of those investigations has been to understand how Saturn formed and evolved and to place Saturn in the context of other gas giants and planetary…
Impact crater counts on the Saturnian satellites are a key element for estimating their surface ages and placing constraints on their impactor population. The Cassini mission radar observations allowed crater counts to be made on the…
From orbit, the visibility of Titan's surface is limited to a handful of narrow spectral windows in the near-infrared (near-IR), primarily from the absorption of methane gas. This has limited the ability to identify specific compounds on…
The surface of Saturn's moon Titan is coated with small molecule organic solids termed cryominerals. Cryominerals play an analogous role to minerals on Earth in Titan's surface geology and geochemistry. To develop a predictive understanding…
Titan's equatorial regions are covered by eastward propagating linear dunes. This direction is opposite to mean surface winds simulated by Global Climate Models (GCMs), which are oriented westward at these latitudes, similar to trade winds…
Saturn's largest moon, Titan, has an Earth-like volatile cycle, but with methane playing the role of water and surface liquid reservoirs geographically isolated at high latitudes. We recreate Titan's characteristic dry hydroclimate at the…
Saturn's rings are rock-poor, containing 90%-95% ice by mass. As a group, Saturn's moons interior to and including Tethys are also about 90% ice. Tethys itself contains <6% rock by mass, in contrast to its similar-mass outer neighbor Dione,…
In this article I summarize the current state of knowledge about the composition of Titan's atmosphere, and our current understanding of the suggested chemistry that leads to that observed composition. I begin with our present knowledge of…
Selk crater is an $\sim$ 80 km diameter impact crater on the Saturnian icy satellite, Titan. Melt pools associated with impact craters like Selk provide environments where liquid water and organics can mix and produce biomolecules like…
Titan's northern high latitudes host many large hydrocarbon lakes. Like water lakes on Earth, Titan's lakes are constantly subject to evaporation. This process strongly affects the atmospheric methane abundance, the atmospheric temperature,…
We apply previously introduced measures of chemical disequilibrium to Cassini mass spectroscopy data on the atmosphere of Titan. In the analysis presented here, we use an improved description, avoiding the meanfield approximation in…
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…
Titan, Saturn's largest satellite, maintains an atmosphere composed primarily of nitrogen (N$_2$) and methane (CH$_4$) that leads to a complex organic chemistry. Some of the nitriles (CN-bearing organics) on Titan are known to have…
We have obtained spatially resolved spectra of Titan in the near-infrared J, H and K bands at a resolving power of ~5000 using the near-infrared integral field spectrometer (NIFS) on the Gemini North 8m telescope. Using recent data from the…
We study the transport of methane in the external water envelopes surrounding water-rich super-Earths and estimate its outgassing into the atmosphere. We investigate the influence of methane on the thermodynamics and mechanics of the water…
The origin of the regular satellites ties directly to planetary formation in that the satellites form in gas and dust disks around the giant planets and may be viewed as mini-solar systems, involving a number of closely related underlying…
Is life a common outcome of physical and chemical processes in the universe? Within our own solar system, a successful search for even primitive life, were it to have an origin independent from life on Earth, would dramatically advance a…
The atmosphere of Titan, the largest moon of Saturn, is rich in organic molecules, and it has been suggested that the moon may serve as an analog for the pre-biotic Earth due to its highly reducing chemistry and existence of global hazes.…
The formation of Saturn is modeled by detailed numerical simulations according to the core-nucleated accretion scenario. Previous models are enhanced to include the dissolution of accreting planetesimals, composed of water ice, rock, and…
Mars finished forming while the solar nebula was still present, and acquired its primordial atmosphere from this reservoir. The absence of a detectable cometary xenon signature in the present-day Martian atmosphere suggests that the capture…