Showing papers in "Icarus in 1974"

TL;DR: The morphologic features of the large Martian channels are shown to be strikingly similar to those of the Channeled Scabland of eastern Washington, produced by the catastrophic breakout floods of Pleistocene Lake Missoula.

TL;DR: In this article, it was shown that a planetary core composed of condensed matter accumulates in the primitive solar nebula, the gas in the nebula becomes gravitationally concentrated as an envelope about the planetary core, and the surrounding gas also may be compressed onto the core by the background pressure of the gas.

TL;DR: A review of the evidence that the earth's atmosphere is regulated by life on the surface so that the probability of growth of the entire biosphere is maximized can be found in this paper.

TL;DR: In this paper, three different diameter size ranges are considered in connection with the Martian crater distribution, taking into account small craters from 0.6 to 1.2 km, intermediate-sized cracers from 4 to 10 km, and large craters with diameters exceeding 20 km.

TL;DR: In this article, a simulation of fluvial erosion features of sinuous rilles on the Moon is presented, showing that sustained flow can result in the incision of a lava channel.

TL;DR: In this paper, the moment of inertia and the hydrostatic value of the second degree harmonic coefficient of Mercury's gravity field are found for the differentiated and undifferentiated models, respectively.

TL;DR: In this article, the authors constructed models of the giant planets based on the assumption that the hydrogen to helium ratio is solar in these planets, together with arguments about the condensation sequence in the primitive solar nebula, yields models with a central core of rock and possibly ice surrounded by an envelope of hydrogen, helium, methane, ammonia and water.

TL;DR: In this article, detailed photochemical models were constructed for two model atmospheres: (1) 100% CH4 and (2) 50% H2, 50% CH 4, which confirm the interpretation by Danielson et al. (1973) of the 12μ feature in the spectra of C2H6 in a thermal inversion region.

TL;DR: In this article, the rotational light curves for Io, Europa, and Ganymede at a mean phase angle of about 6 degrees were obtained by combining their observations with photometry obtained by others over a broader range of phase angles.

TL;DR: In contrast to the earth's atmosphere, the atmosphere of the moon is exceedingly tenuous and appears to consist mainly of noble gases as discussed by the authors, but atmospheric gases containing these elements have not been positively identified.

TL;DR: The radio emission spectra of the J = 1−0 ground state transition of H 12 C 14 N has been detected in comet Kohoutek (1973f) before and after perihelion passage as mentioned in this paper.

TL;DR: In this paper, the spectral reflectivities of Iapetus, Rhea, Dione and Tethys have been obtained for Titan, and the wavelength dependence of its solar phase coefficient has been obtained.

TL;DR: In this article, it was shown that during Jupiter's earliest contraction history, ices would have preferentially been prevented from condensing within the region containing the orbits of the inner satellites and water should be the only ice present in significant proportions in any of the Galilean satellites.

TL;DR: In this paper, an efficient method is proposed for computing the intensity of radiation diffusely reflected from a semi-infinite homogeneous atmosphere with arbitrary phase function, and the results of the brightness distribution over the disk of a planet when the phase angle α = 0, as well as spherical and geometrical albedos and other auxiliary functions.

TL;DR: The wavelength dependence of the reflectivity of Io indicates the presence of two materials on the surface of this satellite of Jupiter: sulfur and an unspecified material (R1) which shows a wavelength dependent of its reflectivity for wavelengths from 0.3 to 1.0 micron similar to the non-H2O frost spectrum of the rings of Saturn as mentioned in this paper.

TL;DR: In this article, a model of streak and splotch formation was proposed on the basis of Mariner 9 data, and the results showed that splotches in the northern to southern midlatitudes closely follow those of bright streaks, suggesting both were formed by similar winds.

TL;DR: The albedo of the dust particles is between 0.10 and 0.20 as discussed by the authors, which indicates that the particles in the coma and the anti-tail of a single comet must be larger than about 10 microns diameter.

TL;DR: In this paper, a model of the behavior of the Martian polar caps is described which incorporates the heating effects of the atmosphere, as well as insolation and conduction, and it predicts that all the seasonally condensed CO2 will be lost by around the summer solstice.

TL;DR: In this article, Hartmann and Soderblom developed computerized cratering-obliteration models for use in interpreting planetary surface histories in terms of the diameter-frequency relations for craters classified by morphology.

TL;DR: Polarimetric measurements were collected at different areas of the surface of Mercury, and for the whole disk in six wavelengths as mentioned in this paper, and the curves of polarization are compared with telescopic observations of the Moon and laboratory studies of minerals and returned lunar samples.

TL;DR: In this paper, a formal expression for the rate of mass accretion by a planet is developed, and a simple and physically reasonable approximate expression for a planetary accretion rate is proposed.

TL;DR: In this paper, the evolution of the protoplanet Jupiter is followed using a hydrodynamic computer code with radiative energy transport, where the initial state has a density of 1.5 × 10 −11 g cm −3 and a temperature of 43 K; the calculations are carried to an equilibrium state where the central density reaches 0.5 g cm−3 and the central temperature reaches 2.5× 10 4 K.

TL;DR: A euphotic zone seems to exist at about 1 cm subsurface in the Martian epilith as mentioned in this paper, where visible light is still intense enough to be utilized by conceivable photosynthetic organisms; but the germicidal ultraviolet intensities at the Martian surface have been reduced to values manageable by terrestrial life.

TL;DR: In this paper, it was shown that the period of premare time during which the vast majority of craters, large and small, were formed was several hundred million years long and the craters of all sizes were formed in exponentially declining numbers during this period with a half life of about 88×106 yr.

TL;DR: In this paper, a control network of 38 landmarks has been established and used to determine the physical size, shape, orientation, libration, and topography properties of Phobos.

TL;DR: In this paper, the authors compare the major features of the two largest Martian dust storms on photographic record, namely those of 1971 and 1973, to facilitate a comparison of their initial outbreaks and growth.

TL;DR: High-resolution radar data, taken from over the 1500-km circular area that was at the center of the planetary disk on June 20, 1972, show that this part of Venus is nearly flat and cratered as discussed by the authors.

TL;DR: In this paper, absolute measurements of the brightness temperatures of the Sun, new Moon, Venus, Mars, Jupiter, Saturn, and Uranus, and the flux density of DR21 at 2.1-mm wavelength are reported.

TL;DR: In this paper, the effects of pressure shifts on the formation of H 2 quadrupole absorption lines in the atmospheres of the major planets have not previously been considered, although pressure shifts have not been measured for the 3-0 and 4-0 H 2 bands, they can be estimated from existing experimental and theoretical knowledge.