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Cruikshank, Dale P.

Publications and source records attributed to Cruikshank, Dale P..

80 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1988

SIRTF and solar system studies

Current objectives of infrared studies of solar system bodies are reviewed, and the contributions in this area that SIRTF can make are addressed. Primordial issues, the evolution of giant planet atmospheres and satellites, seasonal processes in giant planet atmospheres and satellites, the comets, the asteroids, interplanetary matter, and the detection of extrasolar planetary systems are considered. The role of SIRTF in the Comet Rendezvous Asteroids Flyby (CRAF) mission is examined.

Cruikshank, Dale P.↗
NASA NTRS1988

Organic matter in carbonaceous chondrites, planetary satellites, asteroids and comets

A detailed review is given of the organic compounds found in carbonaceous chondrite meteorites, especially the Murchison meteorite, and detected spectroscopically in other solar-system objects. The chemical processes by which the organic compounds could have formed in the early solar system and the conditions required for these processes are discussed, taking into account the possible alteration of the compounds during the lifetime of the meteoroid. Also considered are the implications for prebiotic evolution and the origin of life. Diagrams, graphs, and tables of numerical data are provided.

Cronin, John R.↗
NASA NTRS1987

Water frost on Charon

New spectra of the Pluto-Charon system taken just before and during a total eclipse of the satellite are presented. The spectrum of Charon extracted from the data reveals the signature of water ice. There is no evidence for any methane or ammonia frost on the surface of Charon. The significance of these findings for the evolution of the Pluto-Charon system are discussed.

Buie, Marc W.↗
NASA NTRS1987

A study of the Io-associated plasma and neutral sodium cloud

Narrow-band interference filter images were obtained for the Io torus at the S II wavelengths of 6716, 6731 and at the wavelenght of the S III, 9532 spectrum. The purpose of these observations is to study the short term temporal behavior of the torus and to gain a better understanding of the systematic morphology of the torus. From these images, estimates were obtained for the electron and ion densities and ion temperatures as a function of longitude, latitude, radius from Jupiter, and time. From the analysis of images taken in 1983 and 1984, extremely sharp longitudinal variations in plasma density were detected, subcorotational velocities were measures in the torus plasma, the presence of an optical east-west brightness asymmetry was confirmed in the ion emissions, and longitudinal variations were detected in torus ion temperatures.

Pilcher, Carl B.↗
NASA NTRS1987

The relationship of active comets, 'extinct' comets, and dark asteroids

The possibility of distinguishing between outer solar system asteroids and dark cometary objects is discussed. Planetesimals that could be comets in various evolutionary phases have been detected at distances greater than about 3 AU. Comparisons are made among observed planetesimal and cometary albedos and spectra. It is noted that carbonaceous material, assumed to originate from comets, has been captured in the stratosphere. The data indicate that extinct or dormant comets have loose aggregate surface structures consisting of reddish organic compounds. A protoplanetary nebular condensation scenario is discussed which would have produced the dark cometary bodies.

Hartmann, William K.↗
NASA NTRS1987

Dark matter in the solar system

Many small bodies in the solar system, including planetary satellites, comets, and asteroids, have a surface component consisting at least in part of a very low albedo (0.06 or less) solid substance of neutral or red color in the wavelength region 0.3-2.5 microns. Laboratory spectra of organic residues from meteorites and mixtures with hydrous silicates suggest that complex mixtures of complex organic molecules (kerogens) together with aqueous alteration products of igneous minerals may be the source of the dark matter that is distributed so widely throughout the solar system.

Cruikshank, Dale P.↗
NASA NTRS1986

Satellites of Uranus and Neptune, and the Pluto-Charon system

The orbital properties, surface compositions, opposition surges, masses, radii, and densities of the satellites of Uranus are presented. It is noted that the Uranian satellites are comparable in size to the largest of Saturn's icy satellites while density measurements suggest that the bulk compositions of Ariel and Umbriel might be different from those of Titania and Oberon. Consideration is given to the two satellites of Neptune and the question of a third satellite is addressed. The elements of Charon, determined from astrometric observations by photographic and speckle interferometric techniques, and then from eclipse observations, are given. The diurnal period of Pluto and its photometric lightcurve are discussed. The similarities and differences existing between the satellites of Uranus and Neptune and the Pluto-Charon pair are mentioned briefly.

Cruikshank, Dale P.↗