Events following the giant impact formation of the Moon are thought to have led to volatile depletion and concurrent mass-dependent fractionation of the isotopes of moderately volatile elements (MVE). The detailed processes and conditions surrounding this episode remain obscured and are not unified by a single model for all volatile elements and compounds. Using available data, including new Zn isotope

An ancient Venusian rock could constrain that planet’s history and reveal the past existence of oceans. Such samples may persist on the Moon, which lacks an atmosphere and significant geological activity. We demonstrate that, if Venus’ atmosphere was at any point thin and similar to Earth’s, then asteroid impacts transferred potentially detectable amounts of Venusian surface material to the lunar regolith

Bulk chemical composition is a fundamental property of a planetary material, rock or regolith, and can be used to constrain the properties and history of a material, and by extension its parent body, including its potential for habitability. Here, we investigate how uncertainties in bulk major element analyses can affect inferences derived from those analyses, including rock classification by total-alkalis–silica

We combine experimentally verified constraints on brine thermodynamics along with a global circulation model to develop a new extensive framework of brine stability on the surface and subsurface of Mars. Our work considers all major phase changes (i.e., evaporation, freezing, and boiling) and is consistent, regardless of brine composition, so it is applicable to any brine relevant to Mars. We find

A thermal oscillation in Jupiter’s equatorial stratosphere, thought to have ∼4 Earth year period, was first discovered in 7.8 μ m imaging observations from the 1980s and 1990s. Such imaging observations were sensitive to the 10–20 hPa pressure region in the atmosphere. More recent 7.8 μ m long-slit high-spectroscopic observations from 2012 to 2017 taken using the Texas Echelon cross-dispersed Echelle

Visible near-infrared (Vis–NIR) reflectance spectroscopy is a powerful nondestructive technique allowing the parent bodies identification of cosmomaterials such as meteorites, micrometeorites, and interplanetary dust particles (IDPs) studied in the laboratory. Previous studies showed that meteorites do not represent the full diversity of the solar system small bodies. We present here an experimental

We present 1 mm observations constructed from Atacama Large (sub)Millimeter Array (ALMA) data of SO 2 , SO, and KCl when Io went from sunlight into eclipse (2018 March 20) and vice versa (2018 September 2 and 11). There is clear evidence of volcanic plumes on March 20 and September 2. The plumes distort the line profiles, causing high-velocity (≳500 m s −1 ) wings and red-/blueshifted shoulders in

Near-infrared (NIR) spectrometers on board current sample return missions Hayabusa2 and the Origins-Spectral Interpretation-Resource Identification-Security-Regolith Explorer (OSIRIS-REx) from primitive bodies detected the presence of hydrated silicates on the surface of asteroids Ryugu and Bennu, respectively. These detections relied upon the study of the 2.7 μ m OH-stretching spectral feature, whose

The meteoroid input function (MIF) describes the seasonal, diurnal and planetographic distribution of incoming meteoroids onto an atmosphere and/or surface of a solar system body. Utilizing state-of-the-art dynamical models of the main populations of meteoroids, we present a comparative study of the MIF on the atmospheres of Venus, Earth and Mars. Our modeling results show that, although a planet's

The disequilibrium combination of abundant methane and carbon dioxide has been proposed as a promising exoplanet biosignature that is readily detectable with upcoming telescopes such as the James Webb Space Telescope. However, few studies have explored the possibility of nonbiological CH 4 and CO 2 and related contextual clues. Here we investigate whether magmatic volcanic outgassing on terrestrial

The insoluble organic matter (IOM) contained in carbonaceous chondrites has witnessed a diverse suite of processes possibly starting from the evolution of the parent molecular cloud down to the protosolar nebula and finally to asteroidal processes that occurred on the chondrites’ parent bodies. Laser desorption coupled with ultra-high-resolution mass spectrometry reveals that the IOM of the Paris meteorite

The Main Belt Asteroid (16) Psyche is the target object of the NASA Discovery Mission Psyche. We observed the asteroid at ultraviolet (UV) wavelengths (170–310 nm) using the Space Telescope Imaging Spectrograph on the Hubble Space Telescope during two separate observations. We report that the spectrum is very red in the UV, with a blue upturn shortward of ∼200 nm. We find an absorption feature at 250

Images from the Mercury Dual Imaging System (MDIS) aboard the MErcury Surface, Space ENvironment, GEochemistry, and Ranging mission reveal low-reflectance polar deposits that are interpreted to be lag deposits of organic-rich, volatile material. Interpretation of these highest-resolution images of Mercury’s polar deposits has been limited by the available topography models, so local high-resolution

Lunar cold traps are defined by extremely low time-integrated sublimation loss, so that water ice is expected to accumulate in them. Due to the strong dependence of the sublimation rate on temperature, they have heretofore been delineated by the peak rather than the time-averaged sublimation rate. Here, time-averaged sublimation rates are calculated for the south polar region of the Moon based on 11

Microwave emission of the Moon, measured by the Chang’E-2 Microwave Radiometer (MRM), provides an effective way to understand the physical properties of lunar near-surface materials. The observed microwave brightness temperature is affected by near-surface temperatures, which are controlled by the surface albedo, roughness, regolith thermophysical properties, and the high thermal inertia and permittivity

We have searched a 2010 archival data set from the Canada–France–Hawaii Telescope for very small (km-scale) irregular moons of Jupiter in order to constrain the size distribution of these moons down to radii of ~400 m, discovering 52 objects that are moving with Jupiter-like on-sky rates and are nearly certainly irregular moons. The four brightest detections, and seven in total, were all then linked

We report on the stellar occultation by (523764) 2014 WC 510 observed on 2018 December 1 UT. This occultation campaign was part of the Research and Education Collaborative Occultation Network (RECON), a network of small telescopes spread over 2000 km in western USA and Canada. Light curves from six stations revealed three groups of two or more consecutive flux drops correlated in time between adjacent

The cause of chemical depletion and isotopic fractionation of moderately volatile elements (MVEs) in the Moon is a long-standing problem. Here we examine MVE isotopic fractionation during Moon formation using potassium as a primary example. We show that the degree of isotopic fractionation due to evaporation of the lunar magma ocean (LMO) depended critically on the vapor pressure above the LMO. Based

Observations with Cassini's Electron Spectrometer discovered negative ions in Titan's ionosphere, at altitudes between 1400 and 950 km. Within the broad mass distribution extending up to several thousand amu, two distinct peaks were identified at 25.8–26.0 and 49.0–50.1 amu/q, corresponding to the carbon chain anions CN − and/or ##IMG## [http://ej.iop.org/images/2632-3338/1/2/50/psjabb1baieqn1.gif]

New observing capabilities coming online over the next few years will provide opportunities for characterization of exoplanet atmospheres. However, clouds/hazes could be present in the atmospheres of many exoplanets, muting the amplitude of spectral features. We use laboratory simulations to explore photochemical haze formation in H 2 -rich exoplanet atmospheres at 800 K with metallicity either 100

The detection of biosignatures on a planetary surface is of high scientific interest, and enantiomeric excesses of organic molecules are one such signature. Enantiomeric excesses can be detected by their polarizing effects on transmitted light. As part of instrument development work for a microscopic imager, the Cold Lightweight Imager for Europa (C-LIFE), we assess the potential of polarization measurements

Giant planet migration is an important phenomenon in the evolution of planetary systems. Recent works have shown that giant planet growth and migration can shape the asteroid belt, but these works have not considered interactions between planetesimals. We have calculated the evolution of planetesimal disks, including planetesimal–planetesimal collisions, during gas giant growth and migration. The numbers

A stable population of objects co-orbiting with Venus was recently hypothesized in order to explain the existence of Venus’s co-orbital dust ring. We conducted a five days twilight survey for these objects with the Cerro-Tololo Inter-American Observatory 4 m telescope covering about 35 unique square degrees to 21 mag in the r band. Our survey provides the most stringent limit so far on the number of

In the study of planetary habitability and terrestrial atmospheric evolution, the divergence of surface conditions for Venus and Earth remains an area of active research. Among the intrinsic and external influences on the Venusian climate history are orbital changes due to giant planet migration that have both variable incident flux and tidal heating consequences. Here, we present the results of a

We describe the discovery of a satellite of the Trojan asteroid (3548) Eurybates in images obtained with the Hubble Space Telescope. The satellite was detected on three separate epochs, two in 2018 September and one in 2020 January. The satellite has a brightness in all three epochs consistent with an effective diameter of d 2 = 1.2 ± 0.4 km. The projected separation from Eurybates was s ∼ 1700–2300

A dusty ringlet designated R/2006 S3, also known as the “Charming Ringlet,” is located around 119,940 km from the center of Saturn within the Laplace Gap in the Cassini Division. Prior to 2010, the ringlet had a simple radial profile and a predictable eccentric shape with two components, one forced by solar radiation pressure and the other freely precessing around the planet. However, observations

We provide formulae for the calculation of precise Doppler velocities of sunlight, in both the case of direct observations of the Sun and in reflection from the surfaces of solar system objects such as the Moon or asteroids. We discuss the meaning of a "barycentric correction" of measurements of these Doppler velocities, which is a different procedure from the analogous correction for starlight, and

The Cumberland drill sample from the Sheepbed mudstone in Gale Crater, Mars, revealed the first evidence of an indigenous Martian organic molecule, chlorobenzene, with the Sample Analysis at Mars (SAM) instrument on Curiosity. We created in the laboratory a mineralogical analog of the Cumberland sample (CBA) to aid in the understanding of the precursor organic molecule(s) that led to the detection

We consider whether equilibrium size distributions from collisional cascades match the frequency of impactors derived from New Horizons crater counts on Charon. Using an analytic model and a suite of numerical simulations, we demonstrate that collisional cascades generate wavy size distributions; the morphology of the waves depends on the binding energy of solids ##IMG## [http://ej.iop.org/images/

Astrophysical measurements have shown that some stars have sufficiently high carbon-to-oxygen ratios such that the planets they host would be mainly composed of carbides instead of silicates. We studied the behavior of silicon carbide in the presence of water under the high pressure–temperature conditions relevant to planetary interiors in the laser-heated diamond-anvil cell. When reacting with water

Exoplanet discoveries have reached into the realm of terrestrial planets that are becoming the subject of atmospheric studies. One such discovery is LHS 3844b, a 1.3 Earth radius planet in a 0.46 day orbit around an M4.5-5 dwarf star. Follow-up observations indicate that the planet is largely devoid of substantial atmosphere. This lack of significant atmosphere places astrophysical and geophysical

space-weathering as well as shock effects can darken meteorite and asteroid reflectance spectra. We present a detailed comparative study on shock-darkening and space-weathering using different lithologies of the Chelyabinsk LL5 chondrite. Compared to space-weathering, the shock processes do not cause significant spectral slope changes and are more efficient in attenuating the orthopyroxene 2 μ m absorption

We present the first optical observations taken to characterize the near-Earth object 138175 (2000 EE104). This body is associated with interplanetary field enhancements (IFEs), thought to be caused by interactions between the solar wind magnetic field and solid material trailing in the orbit of the parent body. Based on optical photometry, the radius (in meters) and mass (in kilograms) of an equal-area

We present Cassini Visual and Infrared Mapping Spectrometer (VIMS) observations of sun glitter—wave-induced reflections from a liquid surface offset from a specular point—on Kraken Mare. sun glitter reveals rough sea surfaces around Kraken Mare, namely the coasts and narrow straits. The sun glitter observations indicate wave activity driven by the winds and tidal currents in Kraken Mare during northern

We present Citlalmitl (the word for meteorite in the Nahuatl language), a new experimental device designed and built to simulate high-temperature processes relevant for meteoritics, including chondrule formation and the atmospheric entry of micrometeorites (MMs). The main component of Citlalmitl is a 50 W CO 2 laser, used to melt samples that simulate the precursors of meteoritical materials. As examples

We identify and document the instances of bright ephemeral features (BEF)—bright areas that appear, disappear, and shift from flyby to flyby on Titan's north pole, using the Cassini Visual and Infrared Mapping Spectrometer data set, thereby developing a sense of their spatial distribution and temporal frequency. We find that BEFs have differing geographic location and spatial extents. However, they

Saturn's moon Titan is the only extraterrestrial body known to host stable lakes and a hydrological cycle. Titan's lakes predominantly contain liquid methane, ethane, and nitrogen, with methane evaporation driving its hydrological cycle. Molecular interactions between these three species lead to non-ideal behavior that causes Titan's lakes to behave differently than Earth's lakes. Here, we numerically