Showing papers in "Icarus in 2004"

TL;DR: In this paper, the authors used the most recent data for the rotational state of Mars, and a new numerical integration of the Solar System, to provide a precise solution for the evolution of Mars' spin over 10 to 20 Myr.

TL;DR: In this article, the authors used infrared spectra returned by the Mars Global Surveyor Thermal Emission Spectrometer (TES) to retrieve atmospheric and surface temperature, dust and water ice aerosol optical depth, and water vapor column abundance.

TL;DR: In this article, a hydrodynamic simulation of potential Moon-forming impacts is presented, focusing on the "late impact" scenario in which the lunar forming impact occurs near the very end of Earth's accretion.

TL;DR: One-dimensional aeronomical calculations of the atmospheric structure of extra-solar giant planets in orbits with semi-major axes from 0.01 to 0.1 AU show that the thermospheres are heated to over 10,000 K by the EUV flux from the central star, implying that the upper thermosphere is cooled primarily by adiabatic expansion as discussed by the authors.

TL;DR: In this article, the authors present results from 44 simulations of late stage planetary accretion, focusing on the delivery of volatiles (primarily water) to the terrestrial planets.

TL;DR: In this paper, the authors used the Fourier Transform Spectrometer (FTS) at the Canada-France-Hawaii Telescope (CFIHT) to detect the absorption by martian methane at a 3.7 sigma level, which is exactly centered in the summed spectrum.

TL;DR: In this article, the authors present new visible and near-infrared spectroscopic measurements for 252 near-Earth and Mars-crossing (MC) objects observed from 1994 through 2002 as a complement to the Small Main Belt Asteroid Spectroscopic Survey (SMASS), combined with previously published SMASS results, have an internally consistent data set of more than 400 of these objects for investigating trends related to size, orbits, and dynamical history.

TL;DR: Folkner et al. as discussed by the authors measured the mixing ratios of H2O, H2S, and NH3 in the deep well-mixed atmosphere of Jupiter and showed that the mixing ratio of NH3 increased with depth, finally reaching we ll-fixed equilibration levels at pressures far greater than the lifting condensation levels.

TL;DR: In this article, the authors compared the theoretical estimates of the distribution of ground ice with the observed distribution of leakage neutrons measured by the Neutron Spectrometer instrument of the Mars Odyssey spacecraft's Gamma Ray Spectrometers instrument suite.

TL;DR: Ocean-Planets as mentioned in this paper are a family of exoplanets which is in between the rocky terrestrial planets and the gaseous giants, and they have a density lower than that of rocky planets.

TL;DR: In this article, the results of a visible spectroscopic survey of 820 asteroids carried on between November 1996 and September 2001 at the 1.52 m telescope at ESO (La Silla) are presented.

TL;DR: In this article, Binzel et al. used the largest available data sets for the observed taxonomic and albedo distributions of the near-Earth object population to model the bias-corrected population.

TL;DR: In this paper, the authors studied planetary migration in a gas-free disk of planetesimals and showed that Neptune could have had either a damped migration, limited to a few AUs, or a forced migration up to the disk's edge.

TL;DR: In this paper, coupled thermal-orbital evolution models of Europa and Io are presented, assuming that Io, Europa, and Ganymede evolve in the Laplace resonance and that tidal dissipation of orbital energy is an internal heat source for both Io and Europa.

TL;DR: In this article, the authors analyzed data from the Mars Global Surveyor spacecraft to uncover trends in the dimensional and physical properties of the martian gullies and their surrounding terrain, including apparent source depth and distribution, vertical and horizontal dimensions, slopes, orientations, and present-day characteristics that affect local ground temperatures.

TL;DR: In this paper, the authors present results of 161 numerical simulations of impacts into 100-km diameter asteroids, examining debris trajectories to search for the formation of bound satellite systems using a 3-dimensional smoothparticle hydrodynamics (SPH) code to model the impact between the colliding asteroids.

TL;DR: In this article, the role of surface conductivity in the Yarkovsky-O'Keefe-Radzievskii-i-Paddack (YORP) effect has been analyzed.

TL;DR: In this article, the authors studied the production of potential martian meteorites numerically within the frame of 3D hydrodynamic modeling and found that the ratio of the volume of escaping solid ejecta to projectile volume depends on the impact angle, impact velocity and the volatile content in the projectile and in the target.

TL;DR: In this article, the first ion irradiation experiments performed on natural complex hydrocarbons (asphaltite and kerite) were performed on primitive outer Solar System objects and the results showed that irradiation-induced carbonization gradually neutralizes the spectral slopes of these red organic solids.

TL;DR: In this article, a detailed model of the UVS detector and improved both the data reduction methods and retrieval techniques was developed to resolve inconsistencies that have been noted in the scientific literature and to provide improved constraints for photochemical models and offer a better understanding of Titan's upper atmosphere.

TL;DR: Clancy et al. as discussed by the authors reported the detection of H2O2 on Mars in June 2003, and its mapping over the martian disk using the same technique, during the southern spring (Ls=206°) when the global water vapor abundance was ∼10 pr.

TL;DR: In this paper, the results of low-temperature (18 K) ice energetic processing experiments involving pure HCN and mixtures of HCN with H2 Oa nd NH 3.

TL;DR: In this paper, the authors used the Global Surveyor Thermal Emission Spectrometer (GSES) data of martian surface dust to provide clues to its mineralogy, including the presence of an H2O-bearing mineral.

TL;DR: In this paper, the authors used the Wide Field Camera (WFC) on the Hubble Space Telescope and the Low Resolution Imaging Spectrograph (LRIS) on Keck II telescope to image 21 distant dynamically new, long-period and short-period (SP) Jupiter-family (JF) comet nuclei.

TL;DR: In this article, the results of low-temperature chemistry of acetonitrile, propionitrile and trimethylacetonitriles were investigated in Titan's atmosphere, cometary comae, and the interstellar medium.

TL;DR: In this article, the authors used a simple radiative transfer model to study four micro-habitats in which such a theoretical Martian Earth-like photosynthetic Zone (MEPZ) might exist.

TL;DR: In this paper, an energy-based approach is introduced which is shown to include stability approaches used in the statics of nonlinear elastic and elastic-plastic bodies, spectral definitions and the Liapunov methods used for finite-dimensional dynamical systems.

TL;DR: In this article, Radiative transfer analysis of this line absorption yields an average volume mixing ratio of 18±0.4 ppbv within the lower (0-30 km) Mars atmosphere, in general accordance with standard photochemical models (e.g., Nair et al., 1994, Icarus 111, 124, 150).

TL;DR: In this article, geologic maps from two regional mosaics of Galileo images across the leading and trailing hemispheres of Europa were used to investigate the temporal distribution of units in the visible geologic record.