Showing papers in "Icarus in 2000"

TL;DR: Protostars and Planets VI brings together more than 250 contributing authors at the forefront of their field, conveying the latest results in this research area and establishing a new foundation for advancing our understanding of stellar and planetary formation as mentioned in this paper.

TL;DR: The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect as mentioned in this paper may spin up or spin down 5-km-radius asteroids on a 108-year timescale.

TL;DR: In this paper, the authors investigated the growth time of a bimodal protoplanet-planetesimal system through runaway and oligarchic growth in a 3D N-body simulation with realistic-sized planetesimals with a standard material density.

TL;DR: In this article, high-resolution thermal inertia mapping results are presented, derived from Mars Global Surveyor (MGS) Thermal Emission Spectrometer (TES) observations of the surface temperature of Mars obtained during the early portion of the MGS mapping mission.

TL;DR: In this article, a wide array of scenarios for Europa's chemical evolution in an attempt to explain the presence of ice and hydrated materials on its surface and to understand the physical and chemical nature of any ocean that may lie below.

TL;DR: In this paper, the impact of small fractal aggregates consisting of micrometer-sized dust particles onto solid targets at various velocities was studied in laboratory and microgravity experiments.

TL;DR: In this paper, the authors present an analysis of the distribution of asteroid spin rates vs. size, and find that significant populations of both slow and fast rotators among asteroids smaller than D =40 km, and especially below 10 km.

TL;DR: In this paper, the authors investigated the magnetic field perturbations measured during Galileo flybys of Europa and Callisto are consistent with dipole fields induced by the temporal variations of the ambient jovian magnetospheric field.

TL;DR: The possibility and probability of natural transfer of viable microbes from Mars to Earth and Earth to Mars traveling in meteoroids during the first 0.5 Ga and the following 4 Ga are investigated in this article.

TL;DR: In this paper, numerical simulations of the formation of the planetary companions to 47 UMa, ρ CrB, and 51 Peg are presented for the case of the solid accretion rate, not assumed, and the dissolution of planetesimals within the gaseous envelope is considered.

TL;DR: In this paper, a diurnally averaged model that couples hydrocarbon and oxygen photochemistry, molecular and eddy diffusion, radiative transfer, and condensation was developed to investigate the details of hydrocarbon photochemistry on Saturn, and the model results are compared with observations from the Infrared Space Observatory (ISO) to place tighter constraints on molecular abundances, to better define Saturn's eddy coefficient profile, and to identify important chemical schemes that control the abundances of the observable hydrocarbons in Saturn's upper atmosphere.

TL;DR: The present-day martian UV flux is similar to that of early Earth and thus may not be a critical limitation to life in the evolutionary context, it is a constraint to an unadapted biota and will rapidly kill spacecraft-borne microbes not covered by a martian dust layer.

TL;DR: In this article, a new direct numerical method for simulating planetesimal dynamics in which N ∼10 6 or more bodies can be evolved simultaneously in three spatial dimensions over hundreds of dynamical times is described.

TL;DR: In this article, an extraction system has been constructed that melts ice from the interior of ice cores and collects the resulting water aseptically, using this system, bacteria entrapped in ice cores from different geographic locations, that range in age from 5 to 20,000 years old.

TL;DR: In this paper, the authors investigated the effect of the impact angle on the strength and distribution of the shock wave generated by the impact and found that the volume of impact melt decreases by at most 20% for impacts from 90° down to 45°.

TL;DR: In this paper, an inversion algorithm was proposed for the simultaneous retrieval of the temperature, the para H2 fraction, and the helium abundance from the IRIS spectra alone. But this approach can not be successfully applied to Jupiter because of strong gaseous NH3 and cloud opacity near the low-frequency end of the spectrum, but this restriction is less severe at the lower temperatures of Saturn.

TL;DR: In this paper, the authors presented a model demonstrating how lightning could be generated in the solar nebula which differs from previous models in two important aspects: first, they identified a new, powerful charging mechanism that is based on the differences in contact potentials between particles of different composition, a form of triboelectric charging.

TL;DR: In this article, the authors used Fourier transform laser Raman spectroscopy in the near infrared (1064 nm) to characterize a variety of key pigments and biomolecules produced by cyanobacteria and other stresstolerant microbes in material from extreme Antarctic cold deserts analogous to martian habitats.

TL;DR: These calculations confirm that CO2 clouds should extend the outer boundary of the habitable zone around a star but that there is still a finite limit beyond which above-freezing surface temperatures cannot be maintained by a CO2-H2O atmosphere.

TL;DR: In this paper, the authors analyzed the opposition effect behavior of 33 asteroids with well-measured magnitude-phase curves and found that surface albedo is the main factor influencing the amplitude and width of the asteroid opposition effect.

TL;DR: The Lincoln Near-Earth Asteroid Research (LINEAR) program has applied electro-optical technology developed for Air Force Space Surveillance applications to the problem of discovering near-Earth asteroids (NEAs) and comets.

TL;DR: In this paper, a set of narrowband comet filters, designated the HB filter set, was designed and manufactured to replace aging IHW filters, which were used to measure five different gas species (OH, NH, CN, C2, C3), two ions (CO+, H2O+), and four continuum points.

TL;DR: In this paper, the authors examined the dynamics of a sample of 117 near-Earth objects over a time scale of 60 Myr and found that while 10−20% end their lifetimes by striking a terrestrial planet (usually Venus or Earth), more than half end their lives in a Sun-grazing state, and about 15% are ejected from the Solar System.

TL;DR: In this paper, a new model for the Amazonian outburst floods on Mars is presented, which suggests that CO2 is the active agent in the "floods" rather than water, with the associated difficulties in achieving warm and wet conditions on Mars and on collecting and removing the water before and after the floods.

TL;DR: In this article, the quasi-static equilibrium equations for a body composed of several uniform, Maxwell viscoelastic layers are solved to determine the response of a body to a time-varying potential.

TL;DR: In this paper, the surface ages between the north and south polar layered terrains inferred from crater statistics were investigated and the results were consistent with the hypotheses that polar layered deposit resurfacing rates are highest in areas covered by perennial ice and that the differences in polar resurfacing rate result from the 6.4 km difference in elevation between the polar regions.

TL;DR: In this paper, the authors used spectrophotometrically observed twenty M-class asteroids in the 1.2-to 3.5-μm region, sixteen of them for the first time, and found that over 35% of them have absorption features at 3 μm diagnostic of water of hydration.

TL;DR: In this paper, a diurnally averaged model of photochemistry and diffusion in the stratosphere of Saturn's stratosphere was used to investigate the influence of extraplanetary debris on atmospheric chemistry, in particular the effects of an influx of oxygen from micrometeoroid ablation or from ring-particle diffusion.

TL;DR: In this article, the authors investigate the generation, propagation, and probabilistic hazard of tsunami spawned by oceanic asteroid impacts and derive attenuation relations that account both for geometrical spreading and frequency dispersion of tsunami on uniform depth oceans.

TL;DR: In this article, the first in situ laboratory detection of H 2 O 2 in H + irradiated ices at temperatures relevant to the icy Galilean satellites was presented, motivated by the recent Galileo NIMS detection on Europa of a 3.5-μm band identified with H 2 o 2 (R. W. Carlson et al. 1999, Science 283, 2062-2064).