Showing papers in "Icarus in 2001"

TL;DR: The results of 16 3D N-body simulations of the final stage of the formation of the terrestrial planets are presented in this article, where two initial mass distributions are examined: approximately uniform masses, and a bimodal distribution with a few large and many small bodies.

TL;DR: In this article, the authors consider the hydraulic and thermal conditions that gave rise to the elevated source regions of the Late Hesperian outflow channels and explore their implications for the evolution of the Martian hydrosphere.

TL;DR: In this paper, a simple empirical scattering law is proposed to estimate the rotation period, pole direction, and scattering parameters of an asteroid from its lightcurves simultaneously with the shape.

TL;DR: Galileo Orbiter measurements of energetic ions (20 keV to 100 MeV) and electrons (20-700 keV) in Jupiter's magnetosphere are used, in conjunction with the JPL electron model (less than 40 MeV), to compute irradiation effects in the surface layers of Europa, Ganymede, and Callisto as mentioned in this paper.

TL;DR: In this article, the authors determined the gravity field from the tracking data of previous missions to the Moon with the 1998-1999 Lunar Prospector (LP) mission being the major contributor.

TL;DR: In this article, the authors developed new methods for determining the shapes (and albedo distributions), rotation periods, and pole directions (as well as other parameters, e.g., those of the scattering law) of asteroids from their lightcurves.

TL;DR: Galactic Habitable Zone (GHZ) as mentioned in this paper is a region in the Milky Way where an Earth-like planet can retain liquid water on its surface and provide a long-term habitat for animal-like aerobic life.

TL;DR: In this paper, the authors used N-body integrations to study the effect that planetary embryos spread between 0.5 and 4 AU would have on primordial asteroids, and the most promising model for the formation of the terrestrial planets assumes the presence of such embryos at the time of formation of Jupiter.

TL;DR: The Mars regional atmospheric modeling system (MRAMS) as mentioned in this paper is a mesoscale and cloud-scale model that is widely used for forecasting weather and simulating atmospheric systems over complex terrain.

TL;DR: In this article, the authors used the Goldilocks selection effect to estimate the age distribution of Earth-like planets in the universe and found that three-quarters of all the Earthlike planets are older than the Earth and their average age is 1.8±0.9 billion years older than Earth.

TL;DR: Shkuratov et al. as discussed by the authors used radio wave multiple scattering in the regolith layer to estimate the thickness of regolith on the surface of the Moon and found that the higher the age, the thicker the regool.

TL;DR: In this article, the authors present results of visible wavelength spectroscopic measurements for 48 near-Earth objects (NEOs) obtained with the 5-m telescope at Palomar Mountain Observatory during 1998, 1999, and early 2000.

TL;DR: In this article, the authors present results from a new set of numerical integrations for the dynamical evolution of planetary systems containing two identical giant planets in nearly circular orbits very close to the dynamic stability limit, and conclude that the distributions of eccentricities and semimajor axes for observed systems cannot be explained easily by invoking dynamical interactions between two planets initially on circular orbits.

TL;DR: In this article, radio Doppler data generated by the Deep Space Network (DSN) from five encounters of the Galileo spacecraft with Callisto, Jupiter's outermost Galilean satellite, have been used to determine the quadrupole moments of the satellite's external gravitational field.

TL;DR: In this paper, the authors investigate the hypothesis that the so-called Late Heavy Bombardment (LHB) of the Moon was triggered by the formation of Uranus and Neptune and show that the Moon would have accreted about 6×1021 g, if we assume that the Uranus-Neptune region initially contained 5 times the current mass of these planets in the form of small solid objects.

TL;DR: In this article, a two-dimensional photochemical and transport model was developed to investigate seasonal variations of the composition of Titan's low stratosphere, where large-scale advection, hidden in the vertical eddy diffusion, was accounted for explicitly.

TL;DR: Fegley et al. as discussed by the authors developed a numerical model of the climate evolution of Venus using a one-dimensional two-stream radiative-convective model that treated the transport of thermal infrared radiation in the atmosphere and clouds, and found that the maintenance of sulfuric acid/water clouds on Venus today requires sources of outgassed sulfur active in the past 20−50 Myr.

TL;DR: In this paper, the authors explore the evolution of martian impact crater paleolakes through time by establishing their age, comparing their locations, and describing the formation of lacustrine sedimentary structures and features over time.

TL;DR: In this article, the release of carbon monoxide from Comet C/1995 O1 Hale-Bopp was studied using high-resolution infrared spectroscopy near 4.7 μm.

TL;DR: The Mars Global Surveyor thermal emission spectrometer has been used to track the behavior of surface and atmospheric temperatures, the distribution of condensed CO 2 and H 2 O, and the occurrence of dust storms as discussed by the authors.

TL;DR: In this paper, limits on equilibrium shapes are determined for a cohesionless elastic-plastic solid with a Mohr-Coloumb yield criterion. But the authors do not consider the effect of past history on the shape of the elastic solids.

TL;DR: In this article, the authors investigated the viscosity (the angular momentum flux) in dense, self-gravitating particle disks such as Saturn's main ring, by performing local N-body simulations.

TL;DR: In this paper, the authors constrain the star formation environment of the Sun within the scenario of (external) radioactive enrichment by a massive star using the observed properties of our solar system, in particular the isotopic compositions of meteorites and the regularity of the planetary orbits.

TL;DR: In this paper, an improved statistical method for the calculation of planetary accumulation using the currently standard model of terrestrial planet formation and using the latest results of planetary dynamical theory is presented.

TL;DR: In this article, a five-year study of the temporal stability of Jupiter's zonal wind velocity profile at cloud level based on Hubble Space Telescope images obtained from 1995 to 2000 is presented.

TL;DR: The recently upgraded Arecibo S-band (λ12.6-cm) radar was used to make delay-Doppler images of Mercury's north polar region, where earlier observations had shown strong echoes from putative ice deposits in craters as discussed by the authors.

TL;DR: In this paper, the properties of 4 rings and 16 satellites of Uranus are presented, based on 41 Hubble Space Telescope images taken in 1997 up to 25 filters per object covered the wavelength range 027-2 μm.

TL;DR: McEwen et al. as mentioned in this paper analyzed a collection of hyperspectral images of Io acquired by the near infrared mapping spectrometer (NIMS) of Galileo during the G2 to E16 orbits of Jupiter.

TL;DR: In this paper, the authors presented a new method, termed statistical ranging, applicable to poorly observed single-apparition asteroids having two or more observations, and examined the Bayesian a posteriori probability density of the orbital elements using a Monte Carlo technique that maps an unbiased hypervolume in element phase space.

TL;DR: In this article, the authors studied the survivability of microorganisms of the first step, i.e., the impact ejection, and showed that a substantial fraction of spores are able to survive the severe shock pressure and temperature conditions which must be expected for collisionally produced rock fragments from a medium-sized terrestrial planet that have escape velocities of approximately 5 km/s.