Showing papers in "Icarus in 1979"

TL;DR: In this paper, an expression for the effects of radiation pressure and Poynting-Robertson drag on small, spherical particles using the energy and momentum transformation laws of special relativity is derived.

TL;DR: A crater studies workshop was held for the purpose of developing standardized data analysis and presentation techniques as discussed by the authors, which was devoted primarily to crater size-frequency data and refer to cumulative and relative sizefrequency distribution plots and to morphological analysis.

TL;DR: In this article, it was shown that a main sequence star with a mass less than the Sun has a continuously habitable zone about it which is not only closer in than the corresponding zone about the Sun, but is also relatively narrower.

TL;DR: In this paper, the deceleration and fragmentation of two parent bodies passing through an extended primordial Jovian nebula may account for the clusters of prograde and retrograde satellites of Jupiter.

TL;DR: In this article, a simple analytic model simulating average heat flux from a vigorously convecting mantle and incorporating a mantle viscosity proportional to mantle temperature and a lithosphere which thickens as the planet cools is employed.

TL;DR: In this article, a deformation model is proposed in which a first-order mantle convection cell caused early subcrustal erosion and foundering of the low third of the planet.

TL;DR: In the prebiotic atmosphere of earth ammonia would have been irreversibly converted to N2 in less than 40 years if the ammonia surface mixing ratio were no more than 0.0001 as mentioned in this paper.

TL;DR: In this paper, the authors compared the morphologies of deep-sea channels formed by catastrophic turbidity currents with the Martian channels, and the results indicated that the velocities, discharges, bottom shear stresses, and sediment-transport capacity of water flows along the Mars channels would be comparable to those of the oceanic turbidity current and the Lake Missoula floods.

TL;DR: In this paper, the authors present a detailed analysis of the atmospheric pressure and composition of Mars, and the possibility of a runaway greenhouse effect on Venus resulting in the emplacement of volatiles entirely in the atmosphere is examined.

TL;DR: In this article, the evaporation rate of water ice on the surface of a planet with an atmosphere involves an equilibrium between solar heating and radiative and evaporative cooling of the ice layer.

TL;DR: The location, size and principle characteristics of the currently known proven and probable terrestrial impact craters are compiled in this paper, where a crater is classified as proven if the structure is associated with meteoritic fragments, and probable if shock metamorphic effects are observed in the target rocks.

TL;DR: In this article, the use of infrared techniques to search for nonsolar planets is examined and compared with other possible methods such as long focus astrometry, spectroscopic radial velocity measurements and spaceborne apodization.

TL;DR: Viking Orbiter images have provided nearly complete coverage of the two satellites of Mars and have been used to construct maps of the surface features of Phobos and Deimos as discussed by the authors.

TL;DR: In this paper, the steady state distribution of Apollo-Amor objects is calculated for a variety of possible sources, including asteroids near the inner edge of the belt, cometary orbits similar to Encke, and hypothetical extinct cometary orbit with perihelia larger than that of Encke.

TL;DR: In this article, a modeling technique was developed by which the bulk density, density and temperature profile, rotational moment of inertia, central pressure, and location of the rock-ice interface can all be obtained as a function of the radius, the heliocentric distance, and the silicate composition.

TL;DR: In this article, the shapes and gravitational moments of rotationally and rotationally distorted satellites with nonuniform internal density distributions are calculated. And the shapes of rotational distorted asteroids are discussed briefly.

TL;DR: In this article, a model was developed describing the structure and evolution of isolated giant gaseous protoplanets in the mass range 0.3-4.5 Jovian masses.

TL;DR: Asteroids in general display only small or negligible variations in spectrum or albedo during a rotational cycle as mentioned in this paper, and only 3 Juno, 4 Vesta, 6 Hebe, 71 Niobe, 349 Dembowka, and 944 Hidalgo display color variations larger than 0.03 mag.

TL;DR: In this article, a model for the evolution of the mean rotation rate of asteroids arising from mutual collisions yields reasonable agreement with observed rotation rates, since collisional erosion of small asteroids is more rapid than collisional spin-up.

TL;DR: The terrestrial crater production rate is estimated from a compilation of the locations and ages of proven and probable terrestrial impact craters and compared with that calculated from astronomical observations and for other planets as discussed by the authors.

TL;DR: In this paper, the authors traced the statistical error in Mariner 10 occultation profiles from initial observations to reduced temperature, pressure, and absorption profiles, and concluded that if the systematic error can be reduced to the level of the statistical noise in MARINER 10, then long term studies of thick atmospheres by occultation techniques will be feasible in the future at good levels of accuracy.

TL;DR: In this paper, the authors reconstructed a layered-crust model from bottom to top as: (A) Mg-rich diogenite layer with orthopyroxenes with or without exsolution lamellae of augite with common (100) plane; (B) Fe-rich deformed diogenites with inverted low-Ca pigeonites and orthoproxenes; (C) cumulate eucrite layer with low- Ca inverted pigeonites with blebby augite inclusions with 100 in common generally, and plagioclase (Binda

TL;DR: In this paper, a simple model of a spherical rotating nucleus is formulated and a trial-and-error technique is devised to determine the axis-orientation constants and a lag angle, a measure of the time lag in units of the rotation period.

TL;DR: In this article, the morphologies of smaller Martian volcanoes are discussed as possible results of explosive volcanic density currents, and newly-photographed flank and caldera features reveal their similarity to terrestrial cones and composite volcanoes such as Barcena Volcano.

TL;DR: In this article, it is suggested that Phobos and Deimos are carbonaceous asteroids captured by drag in an extended protoatmosphere of solar composition, and the time scales for regularization of the orbital parameters are estimated, and found to be of the order of a few years.

TL;DR: In this article, the steady state thickness and vertical structure of Saturn's rings are discussed with regard to whether a collapse to a monolayer due to particle collisions may be prevented by various mechanisms.

TL;DR: In this paper, the authors presented a survey of 182 asteroids whose rotational properties are available in the literature, and provided plots for the asteroid rotational frequency f and lightcurve amplitude Δm versus asteroid size; the latter is determined using standard methods if data are available but otherwise is estimated from asteroid albedos, selected depending on taxonomic type or orbital position.

TL;DR: In this paper, an investigation of the Martian polar cap winds and their response to a variety of factors is carried out by numerical experiments based on a zonally symmetric primitive equation model.

TL;DR: In this article, the thermodynamics of graphite, carbide, and carbonate formation in the presence of a solar-composition gas is examined, including the feasibility of producing solid solutions of carbon and carbides in metallic iron-nickel alloy.

TL;DR: In this article, the experimental results of the far ultraviolet photolysis of methane diluted 1000 times with argon were presented for temperatures of 300 and 200°K, and the authors found that both ethylene and acetylene reached a temperature-dependent steady state, while ethane and propane continued to rise linearly with time.