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We present observations of Neptune’s 1- and 3-mm spectrum from the Combined Array for Research in Millimeter-wave Astronomy (CARMA). Radiative transfer analysis of the CO (2–1) and (1–0) rotation lines was performed to constrain the CO vertical abundance profile. We find that the data are well matched by a CO mole fraction of 0.1-0.1+0.2 parts per million (ppm) in the troposphere, and 1.1-0.3+0.2...
Saturn’s proton radiation belts extend over the orbits of several moons that split this region of intense radiation into several distinct belts. Understanding their distribution requires to understand how their particles are created and evolve. High-energy protons are thought to be dominantly produced by cosmic ray albedo neutron decay (CRAND). The source of the lower energies and the role of other...
Trans-neptunian objects (TNOs) are a population of small objects orbiting the Sun beyond Neptune. Because of their distance they are difficult to observe spectroscopically, but a large body of photometric observations is available and growing. TNOs are important tracers of the evolution of the outer Solar System and key when testing current dynamical evolution theories. Previous statistical studies...
On the basis of geological evidence, it is often stated that the early martian climate was warm enough for liquid water to flow on the surface thanks to the greenhouse effect of a thick atmosphere. We present 3D global climate simulations of the early martian climate performed assuming a faint young Sun and a CO 2 atmosphere with surface pressure between 0.1 and 7bars. The model includes a...
Spectral analysis of Mare Serenitatis has been carried out using Chandrayaan-1 Moon Mineralogy Mapper (M 3 ) data in order to map the compositional diversity of the basaltic units that exist in the basin. Mare Serenitatis is characterized by multiple basaltic flows of different ages indicating a prolonged volcanism subsequent to the basin formation event. Reflectance spectra of fresh craters...
Observations of the Moon obtained by the Moon Mineralogy Mapper (M 3 ) instrument were acquired at various local viewing geometries. To compensate for this, a visible near-infrared photometric correction for the M 3 observations of the lunar surface has been derived. Images are corrected to the standard geometry of 30° phase angle with an incidence of 30° and an emission of 0°. The...
An essential role in the asteroidal dynamics is played by the mean motion resonances. Two-body planet–asteroid resonances are widely known, due to the Kirkwood gaps. Besides, so-called three-body mean motion resonances exist, in which an asteroid and two planets participate. Identification of asteroids in three-body (namely, Jupiter–Saturn–asteroid) resonances was initially accomplished by Nesvorný...
The main objective of this study is to develop a new photometric correction that is suitable for global Chang’ E-1 (CE-1) Interference Imaging Spectrometer (IIM) data. We considered two improvements in the accuracy of the photometric correction: (1) classifying the whole Moon’s surface into four classes (very bright rays, mature highlands, low FeO basalts, and high FeO basalts) based on the FeO contents;...
The Lunar Reconnaissance Orbiter Camera (LROC) provides multi-temporal and high resolution imaging of the north and south polar regions. These images delimit illuminated areas from those in shadow, and are used to analyze the illumination environment of the polar regions over the course of a lunar year. The Wide Angle Camera (WAC) provides repeat imaging of the north and south pole at a frequency...
The unusual shape of the Moon given its present rotational and orbital state has been explained as due to a fossil figure preserving a record of remnant rotational and tidal deformation (Jeffreys, H. [1915]. Mem. R. Astron. Soc. 60, 187–217; Lambeck, K., Pullan, S. [1980]. Phys. Earth Planet. Interiors 22, 29–35; Garrick-Bethell, I., Wisdom, J., Zuber, M.T. [2006]. Science 313, 652–655). However,...
We observed the products C 4 H 5 , C 4 H 4 , C 3 H 3 and CH 3 of the C( 3 P)+C 3 H 6 reaction using product time-of-flight spectroscopy and selective photoionization. The identified species arise from the product channels C 4 H 5 +H, C 4 H 4 +2H and C 3 H 3 +CH 3 ...
Near-Earth Asteroids (NEAs) offer insight into a size range of objects that are not easily observed in the main asteroid belt. Previous studies on the diversity of the NEA population have relied primarily on modeling and statistical analysis to determine asteroid compositions. Olivine and pyroxene, the dominant minerals in most asteroids, have characteristic absorption features in the visible and...
Aluminous clay deposits on Mars are recognized from remotely sensed infrared spectral features similar to those of montmorillonite, beidellite, and/or kaolinite. The nature of aluminous clay deposits on Mars is of interest because they likely indicate a different formation mechanism than that of Fe–Mg clays, which are widespread on Mars and likely alteration products of the Fe–Mg-rich basaltic crust...
We present a study of water vapour in the Venus troposphere obtained by modelling specific water vapour absorption bands within the 1.18μm window. We compare the results with the normal technique of obtaining the abundance by matching the peak of the 1.18μm window. Ground-based infrared imaging spectroscopy of the night side of Venus was obtained with the Anglo-Australian Telescope and IRIS2 instrument...
This is an experimental study of ice grain ejection when trapped gases are released from water ice. When ice is formed by adherence of water molecules at low temperatures, it forms an amorphous structure with many pores, where gas molecules can reside. When further ice layers are formed, the gases are trapped in the ice. Upon its warming-up, the ice structure changes, releasing fractions of the trapped...
The Direct Simulation Monte Carlo (DSMC) technique is used here to describe the transition region in Titan’s atmosphere where the gas flow goes from being collisional to collisionless. We expand on our previous study (Tucker, O.J., Johnson, R.E. [2009]. Planet. Space Sci. 57, 1889–1894) by including H 2 in addition to CH 4 and N 2 . We again find that thermal escape of CH ...
We describe a new approach to estimate asteroid masses from planetary range measurements. The approach significantly simplifies the process of parameter estimation and allows an effective control of systematic errors introduced by the omission of asteroids from the dynamical model. All asteroid masses are adjusted individually thus avoiding the usual distinction between masses considered individually...
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