相关论文: Titan brighter at twilight than in daylight
Saturn's largest satellite, Titan, has stratospheric wind speeds that may be up to ~210 m/sec [1], circling Titan in about a day compared to Titan's slow 16-day rotation. Theoretical models to explain such super-rotating winds are not well…
Titan's atmosphere is optically thick and hides the surface and the lower layers from the view at almost all wavelengths. However, because gaseous absorptions are spectrally selective, some narrow spectral intervals are relatively…
Recently, properties of exoplanet atmospheres have been constrained via multi-wavelength transit observation, which measures an apparent decrease in stellar brightness during planetary transit in front of its host star (called transit…
We have analyzed the complete archive of the Visual and Infrared Mapping Spectrometer (VIMS) data in order to monitor and analyze the evolution of the clouds and haze coverage at both poles of Titan during the entire Cassini mission. Our…
In Titan's nitrogen-methane atmosphere, photochemistry leads to the production of complex organic particles, forming Titan's thick haze layers. Laboratory-produced aerosol analogs, or "tholins", are produced in a number of laboratories;…
Volatile organic molecules formed by photochemistry in the upper atmosphere of Titan can undergo condensation as pure ices in the stratosphere and the troposphere as well as condense as ice layers onto the organic aerosols that are visible…
The details of the Solar system's formation are still heavily debated. Questions remain about the formation locations of the giant planets, and the degree to which volatile material was mixed throughout the proto-planetary system. One…
Orbital variation in reflected starlight from exoplanets could eventually be used to detect surface oceans. Exoplanets with rough surfaces, or dominated by atmospheric Rayleigh scattering, should reach peak brightness in full phase, orbital…
Reflected light curves observed for exoplanets indicate bright clouds at some of them. We estimate how the light curve and total stellar heating of a planet depend on forward and backward scattering in the clouds based on Pioneer and…
Cassini-Huygens data are used to re-examine the potential sources of the D/H enhancement over solar, measured in methane, in Titan's atmosphere. Assuming that the system is closed with respect to carbon, the use of constraints from the…
The reflected light signal from a planet throughout its orbit is a powerful probe of a planet's atmospheric properties. There are a number of planets that are amenable to reflected light phase curve studies with present and future…
After 9 years in the Saturn system, the Cassini spacecraft finally observed Titan in the supersonic solar wind. These unique observations reveal that Titan interaction with the solar wind is in many ways similar to un-magnetized planets…
In this paper we select large spectral averages of data from the Cassini Composite Infrared Spectrometer (CIRS) obtained in limb-viewing mode at low latitudes (30S--30N), greatly increasing the path length and hence signal-to-noise ratio…
Titan is regarded as a natural laboratory in the Solar System for studying atmospheric photochemistry and the abiotic production of organic molecules on cold small exoplanets. Since the end of the Cassini-Huygens mission, telescope…
We present the results of the optical spectropolarimetry of Earthshine on the Moon for Earth phase angles ranging from 49 to 96 degrees. The observations were conducted on 2011 March 9-13 (UT) using the spectropolarimeter HBS installed on…
Saturn's moon Titan possesses stratospheric zonal winds that places it among a sparse class of planetary bodies known to have superrotation in their atmospheres. Few measurements have been made of these speeds in the upper stratosphere,…
Earthshine is the dominant source of natural illumination on the surface of the Moon during lunar night, and at locations within permanently shadowed regions that never receive direct sunlight. As such, earthshine may enable the exploration…
The Cassini Composite Infrared Spectrometer (CIRS) observed thermal emission in the far- and mid-infrared (from 10 cm$^{-1}$ to 1500 cm$^{-1}$), enabling spatiotemporal studies of ethane on Titan across the span of the Cassini mission from…
The temperature structure of Titan's upper atmosphere exhibits large variability resulting from numerous spatially and temporally irregular external energy sources, seasonal changes, and the influence of molecular species produced via…
Recognizing whether a planet can support life is a primary goal of future exoplanet spectral characterization missions, but past research on habitability assessment has largely ignored the vastly different conditions that have existed in…