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The source of the unusually high radar reflectivity signal found on the highlands of Venus is hypothesized to be caused by a mineral with a high dielectric constant. We propose that this source could be a combination of tellurium, sulfur, and bismuth. All three elements are commonly outgassed in terrestrial eruption plumes and thus are likely to be found on Venus. To test our hypothesis, we used a...
Several icy bodies in the outer Solar system have extensive internal oceans. In several bodies the oceans are believed to be so extensive they decouple the interior core from the icy surface. A major evolutionary driver in the Solar System is high speed impacts – which lead to cratering or even disruption of the target body. Here we consider how the presence of an internal ocean modifies the energy...
Theoretical carbon dioxide broadened line widths of carbonyl sulfide molecule are reported at the room temperature for wide ranges of rotational quantum numbers (0 ≤ J ≤ 100) requested by spectroscopic databases. To get the temperature-dependence exponents, computations with the room-temperature parameters’ values are repeated for various temperatures characteristic of the Earth and Venus atmospheres...
Akaganeite has been found in Yellowknife Bay mudstones of the Gale crater by the Chemistry and Mineralogy X-ray diffraction instrument (CheMin) aboard the Curiosity rover. This phase has also been discovered in limited locations on Mars by the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter. Akaganeite has also been proposed as a precursor candidate...
This study deals with an aspect of blocks observed on many rocky planetary surfaces: in situ fragmentation. Using LROC/NAC images, we characterized the morphology, morphometry and abundance of in-situ fractured blocks observed on the rim of six large impact craters of known emplacement age on the Moon. The relative number of disrupted blocks increases with crater-retention age of surfaces on which...
Using Gaussian process regression to analyze the Martian surface methane Tunable Laser Spectrometer (TLS) data reported by Webster et al. (2018), we find that the TLS data, taken as a whole, do not indicate seasonal variability. Enrichment protocol CH 4 data are consistent with either stochastic variation or a spread of periods without seasonal preference.
Moist convective storms in Jupiter develop frequently and can trigger atmospheric activity of different scales, from localized storms to planetary-scale disturbances including convective activity confined inside a larger meteorological system. In February 2018 a series of convective storms erupted in Jupiter’s South Temperate Belt (STB) (planetocentric latitudes from − 23 ° to − 29 . 5 ° ). This...
Odd oxygen (O, O( 1 D), O 3 ) abundance and its variability in the Martian atmosphere results from complex physical and chemical interactions among atmospheric species, which are driven mainly by solar radiation and atmospheric conditions. Although our knowledge of Mars’ ozone distribution and variability has been significantly improved with the arrival of several recent orbiters, the data acquired...
Asteroid pairs are those found to share similar heliocentric orbits but not positions. The leading theory suggests that each had a single progenitor that split due to rotational-fission of a weak, rubble-pile structured body. By constructing shape models of asteroid pairs from multiple-apparition observations and using a lightcurve inversion technique, we mapped the gravitational and rotational accelerations...
Ordinary chondrites comprise a significant fraction (~75%) of meteorites that fall on the Earth. A key goal in small body science is to link meteorites to their parent bodies in order to understand their formation conditions early in our Solar System history. Dunn et al. (2010a) provided a robust set of equations for deriving olivine/pyroxene chemistry and abundance ratio from visible and near-infrared...
We have acquired a comprehensive laboratory bidirectional measurements of Apollo 11 and Apollo 16 lunar soil samples and have successfully fit photometric models to the laboratory data and have determined the solar spectrum averaged hemispheric reflectance as a function of incidence angle. The Apollo 11 (sample 10,084) and 16 (sample 68,810) soil samples are two representative end member samples from...
The Nili Fossae region of Mars exhibits from remote sensing spectral data the largest exposures of olivine-rich materials on the planet. However, it is not clearly constrained how and when these terrains formed. Some of the proposed scenarios favor a mode of formation closely related to Isidis impact basin: either under intense effusive volcanism following the impact, from cooling of an immediate...
We investigate the modelled impact on the global atmosphere of local dust storm simulations on the martian atmosphere. The investigation utilises existing observations from Mars Global Surveyor’s Mars Orbiter Camera and the Thermal Emission Spectrometer instruments, and the UK version of the LMD Mars Global Circulation Model. A typical example investigated here is a local dust storm in the Terra Sirenum...
The Japan Aerospace Exploration Agency’s (JAXA) Kaguya spacecraft carried a suite of instruments to map the Moon and its environment globally. During its extended mission, the average altitude was 50 km or lower, and Kaguya science products using these data hence have an increased spatial resolution. However, the geodetic position quality of these products is much worse than that of those acquired...
The high-pressure behaviour of hydrated magnesium sulfate kieserite, MgSO 4 ⋅H 2 O, has been investigated on isothermal compression at T = 295 K up to 8.3 GPa hydrostatic pressure. The crystal properties of synthetic endmember single crystals were investigated using a high-pressure diamond anvil cell by means of in-situ X-ray diffraction and vibrational spectroscopy methods. The experimental study...
We respond to the comments in Ruiz et al. (2018), which claimed that our predicted heat flow values for Venus and ancient Mars (Karimi et al., 2016; Karimi and Dombard, 2017) are unphysically high and would cause melting within the crust. We expand the existing methodology of Karimi et al. (2016) and clarify points in that article regarding our geodynamic modeling. We provide sufficient explanation...
We examine Saturn's atmospheric dynamics with observations in the visible range from ground-based telescopes and Hubble Space Telescope (HST). We present a detailed analysis of observations acquired during 2018 obtaining drift rates of major meteorological systems from the equator to the north polar hexagon. A system of polar storms that appeared in the planet in March 2018 and remained active with...
We measured the degree of linear polarization P of comet C/2018 V1 (Machholz-Fujikawa-Iwamoto) with the broadband Johnson V filter in mid-November of 2018. Within a radius of ρ ≈ 17,000 km of the inner coma, we detected an extremely low linear polarization at phase angles α ≈ 83°–91.2° and constrained the polarization maximum to P max ≈ (6.8 ± 1.8)%. This is the lowest P max ever measured in a comet...
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