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Context. More than 15 years after its landing on the surface of Titan, the data returned by the Huygens probe remain the only available in situ information on Titan's lower atmosphere and its methane content. Aims. In this work, we present a reanalysis of the Huygens probe data obtained by the Gas Chromatograph Mass Spectrometer (GCMS) instrument on board Huygens. GCMS measured the atmospheric composition almost continuously during the Huygens probe descent by acquiring mass spectra between 145 km of altitude and Titan's surface. We first focus on the recollection, reconstruction, and recalibration of the GCMS dataset to facilitate similar future work. Methods. We then reevaluate the methane vertical profile in Titan's lower atmosphere by applying novel mass spectra data-treatment methods to this dataset. Results. In addition to finding a slightly lower methane mixing ratio than those previously reported using GCMS measurements above the Huygens probe landing site, our work has revealed several kilometric to subkilometric-scale oscillations in the methane vertical profile below 30 km of altitude. Conclusions. We discuss several hypotheses that could explain these features, such as multiple layers of optically thin clouds or local convection cells, and strongly encourage the reanalysis of other Huygens datasets to further investigate these variations in the methane mixing ratio. [ABSTRACT FROM AUTHOR]

Robotic spacecraft enable exploration of our Solar System beyond our human presence. Although spacecraft have explored every planet in the Solar System, the frontiers of space robotics are at the cutting edge of landers, rovers, and now atmospheric explorers, where robotic spacecraft must interact intimately with their environment to explore beyond the reach of flyby and orbital remote sensing. Here, we describe the tremendous growth in space robotics missions in the past 7 years, with many new entities participating in missions to the surface of the Moon, Mars, and beyond. We also describe the recent development of aerial missions to planets and moons, as exemplified by the Ingenuity helicopter on Mars and the Dragonfly mission to Titan. We focus on suborbital robotics—landers, rovers, and aerial vehicles—with associated challenges in sensing, manipulation, mobility, and system-level autonomy. [ABSTRACT FROM AUTHOR]

Very-low-mass stars (those less than 0.3 solar masses) host orbiting terrestrial planets more frequently than other types of stars. The compositions of those planets are largely unknown but are expected to relate to the protoplanetary disk in which they form. We used James Webb Space Telescope mid-infrared spectroscopy to investigate the chemical composition of the planet-forming disk around ISO-ChaI 147, a 0.11-solar-mass star. The inner disk has a carbon-rich chemistry; we identified emission from 13 carbon-bearing molecules, including ethane and benzene. The high column densities of hydrocarbons indicate that the observations probe deep into the disk. The high carbon-to-oxygen ratio indicates radial transport of material within the disk, which we predict would affect the bulk composition of any planets forming in the disk. [ABSTRACT FROM AUTHOR]

A theoretical investigation of nonplanar (cylindrical and spherical) amplitude modulation of dust acoustic waves (DAWs) in a four component dusty plasma including positive and negative dusts, Maxwellian ions and double spectral electron distribution (DSED) is carried out. The focusing modified nonlinear Schrödinger equation (MNLSE) is derived using the derivative expansion perturbation technique (DEPT). The limit of DSED to Maxwell distribution is discussed. The effects of the two spectral indices, $ r $ r and $ q $ q , on the modulational instability (MI) growth rate are examined and it is deduced that increasing the value of $ r $ r and $ q $ q raises the MI growth rate. Additionally, the structure of the first and second-order dust acoustic (DA) rogue waves in the modulational unstable region is analyzed. The influences of both of $ r $ r and $ q $ q on the rogue wave amplitude (energy) are investigated. We found that increasing the value of $ r $ r enhances the rogue wave amplitude while the opposite behavior is found by increasing $ q $ q values. The findings of the present study are useful to interpret some physical phenomena in various plasma situations that found in space regions, such as Titan (the largest moon) of Saturn, auroral region and asteroid zones, where the effectiveness of non-Maxwellian particles such as DSED is existed. [ABSTRACT FROM AUTHOR]

The article titled "Sky Notes" provides a comprehensive guide to the celestial objects visible in the night sky during the summer season. It includes information on stars, clusters, and comets in the Ophiuchus constellation, as well as the positions and movements of planets like Saturn, Jupiter, and Mars. The article also mentions upcoming meteor showers and provides details about the Sun and Moon during the months of June and July. This text is a valuable resource for library patrons interested in observing and studying the night sky. [Extracted from the article]

The Earth is no longer the only known celestial body containing one or more liquid phases. The Cassini spacecraft has discovered seas of hydrocarbons at the surface of Titan, while a series of corroborating evidences argue in favor of the existence of an aqueous ocean beneath the icy crust of several moons. Capillarity embraces a family of physical processes occurring at the free surface of a liquid. These phenomena depend on the liquid properties and on the local planetary conditions. Capillarity may have important direct or indirect implications on the geoscientific and astrobiological points of view. In this paper, we discuss capillarity physics among solar system objects and expected consequences for planetary science. Plain Language Summary: The formation of raindrops, the production of tiny liquid droplets by bubble bursting at the surface of an ocean, or even the floatation of small solid particles at this surface, are examples of capillarity effects, physical processes which can be observed in everyday life. In this work, we discuss such phenomena in extraterrestrial contexts where large amount of liquids have be detected during past decades by space exploration. Key Points: Capillarity is involved in numberless natural processesDuring past decades, the presence of liquid phase of different nature has been detected on several extraterrestrial bodies of the solar systemWe review and discuss physical processes that may have important consequences in planetary science like the transport of organic material between planetary interior and the atmosphere [ABSTRACT FROM AUTHOR]

Turbulent fluxes of heat, momentum, and humidity in the atmospheric boundary layer are pivotal to the evolution of geology, weather and climate, and the possibility of life. Here we extend recent advances in calculating these near‐surface turbulent fluxes in the Earth's atmospheric boundary layer to any terrestrial planetary body with an atmosphere. These improvements include: (a) incorporating Monin‐Obukhov similarity functions that encompass the entire range of atmospheric stability expected on terrestrial planetary bodies, (b) accounting for the additional shear associated with buoyant plumes under unstable conditions, (c) using surface renewal theory to calculate transfer rates within the interfacial layer adjacent to the surface, and (d) explicitly accounting for key humidity effects that become especially important when a volatile is more buoyant than the ambient gas (e.g., on Mars where H2O is lighter than CO2). We tested and validated our model using in situ data collected on Earth, Mars, and Titan under a wide range of atmospheric stability, pressure, and surface roughness conditions. The model shows up to 71% better agreement with measurements compared to methods commonly used on Mars for evaporation/sublimation. Compared to previous estimates for H2O ice on Mars, our model predicts up to 1.5–190x lower latent heat fluxes under stable atmospheric conditions (depending on the wind speed) and 1.78x higher latent heat fluxes under unstable conditions. Our results provide improved constraints on the stability of ice on Mars and will help determine whether ice can melt under present‐day conditions. Plain Language Summary: As air flows over a surface, the resulting turbulent eddies cause the air to mix. The intensity of turbulence generated dictates the rate at which energy is given to, or taken away from the surface. If there are volatiles such as liquid water at the surface, then the magnitude of the turbulent fluxes determines how long the volatiles will remain stable before evaporating or freezing. We applied recent advances made on Earth to develop a model for predicting turbulent fluxes and evaporation rates on any planetary body with an atmosphere. To check whether our simulations are accurate, we compared them with measurements made on Earth, Mars and Titan. We found that our simulations agreed up to 71% better with measurements compared to previously developed models used for Mars evaporation. Our simulations predict significantly higher or lower rates of evaporation when compared to previous estimates, depending on atmospheric conditions. These results provide improved constraints on the stability of ice on Mars and will help determine whether ice can melt under present‐day conditions. Key Points: We present an improved model to predict atmospheric turbulent fluxes and evaporation/sublimation rates on any terrestrial planetary bodyThe model shows up to 71% better agreement with measurements compared to methods commonly used on Mars for evaporation and sublimationOur results provide improved constraints on the stability of Martian ice and will help determine whether ice can melt on Mars at present [ABSTRACT FROM AUTHOR]

Tidal interactions between moons and planets can have major effects on the orbits, spins, and thermal evolution of the moons. In the Saturn system, tidal dissipation in the planet transfers angular momentum from Saturn to the moons, causing them to migrate outwards. The rate of migration is determined by the mechanism of dissipation within the planet, which is closely tied to the planet's uncertain structure. We review current knowledge of giant planet internal structure and evolution, which has improved thanks to data from the Juno and Cassini missions. We discuss general principles of tidal dissipation, describing both equilibrium and dynamical tides, and how dissipation can occur in a solid core or a fluid envelope. Finally, we discuss the possibility of resonance locking, whereby a moon can lock into resonance with a planetary oscillation mode, producing enhanced tidal migration relative to classical theories, and possibly explaining recent measurements of moon migration rates. [ABSTRACT FROM AUTHOR]

Here we present the current state of knowledge on the long-term evolution of Saturn's moon system due to tides within Saturn. First we provide some background on tidal evolution, orbital resonances and satellite tides. Then we address in detail some of the present and past orbital resonances between Saturn's moons (including the Enceladus-Dione and Titan-Hyperion resonances) and what they can tell us about the evolution of the system. We also present the current state of knowledge on the spin-axis dynamics of Saturn: we discuss arguments for a (past or current) secular resonance of Saturn's spin precession with planetary orbits, and explain the links of this resonance to the tidal evolution of Titan and a possible recent cataclysm in the Saturnian system. We also address how the moons' orbital evolution, including resonances, affects the evolution of their interiors. Finally, we summarize the state of knowledge about the Saturnian system's long-term evolution and discuss prospects for future progress. [ABSTRACT FROM AUTHOR]

The interior oceans of several icy moons are considered as affected by rotation. Observations suggest a larger heat transport around the poles than at the equator. Rotating Rayleigh‐Bénard convection (RRBC) in planar configuration can show an enhanced heat transport compared to the non‐rotating case within this "rotation‐affected" regime. We investigate the potential for such a (polar) heat transport enhancement in these subglacial oceans by direct numerical simulations of RRBC in spherical geometry for Ra = 106 and 0.7 ≤ Pr ≤ 4.38. We find an enhancement up to 28% in the "polar tangent cylinder," which is globally compensated by a reduced heat transport at low latitudes. As a result, the polar heat transport can exceed the equatorial by up to 50%. The enhancement is mostly insensitive to different radial gravity profiles, but decreases for thinner shells. In general, polar heat transport and its enhancement in spherical RRBC follow the same principles as in planar RRBC. Plain Language Summary: The icy moons of Jupiter and Saturn like for example, Europa, Titan, or Enceladus are believed to have a water ocean beneath their ice crust. Several of them show phenomena in their polar regions like active geysers or a thinner crust than at the equator, all of which might be related to a larger heat transport around the poles from the underlying ocean. We simulate the flow dynamics and currents in these subglacial ocean by high‐fidelity simulations, though still at less extreme parameters than in reality, to study the heat transport and provide a possible explanation of such a "polar heat transport enhancement." We find that the heat transport around the poles can be up to 50% larger than around the equator, and that the believed properties of the icy moons and their oceans would allow polar heat transport enhancement. Therefore, our results may help to improve the understanding of ocean currents and latitudinal variations in the oceanic heat transport and crustal thickness on icy moons. Key Points: The polar heat transport in spherical rotating Rayleigh‐Bénard convection experiences an enhancement by rotationThe influence of rotation differs at low latitudes: the heat flux is reduced and compensates the polar enhancement on the global averageIn combination, this strengthens the latitudinal variation between polar and equatorial heat flux for Prandtl numbers larger than unity [ABSTRACT FROM AUTHOR]

The 2-week, virtual Future of the Search for Life science and engineering workshop brought together more than 100 scientists, engineers, and technologists in March and April 2022 to provide their expert opinion on the interconnections between life-detection science and technology. Participants identified the advances in measurement and sampling technologies they believed to be necessary to perform in situ searches for life elsewhere in our Solar System, 20 years or more in the future. Among suggested measurements for these searches, those pertaining to three potential indicators of life termed "dynamic disequilibrium," "catalysis," and "informational polymers" were identified as particularly promising avenues for further exploration. For these three indicators, small breakout groups of participants identified measurement needs and knowledge gaps, along with corresponding constraints on sample handling (acquisition and processing) approaches for a variety of environments on Enceladus, Europa, Mars, and Titan. Despite the diversity of these environments, sample processing approaches all tend to be more complex than those that have been implemented on missions or envisioned for mission concepts to date. The approaches considered by workshop breakout groups progress from nondestructive to destructive measurement techniques, and most involve the need for fluid (especially liquid) sample processing. Sample processing needs were identified as technology gaps. These gaps include technology and associated sampling strategies that allow the preservation of the thermal, mechanical, and chemical integrity of the samples upon acquisition; and to optimize the sample information obtained by operating suites of instruments on common samples. Crucially, the interplay between science-driven life-detection strategies and their technological implementation highlights the need for an unprecedented level of payload integration and extensive collaboration between scientists and engineers, starting from concept formulation through mission deployment of life-detection instruments and sample processing systems. [ABSTRACT FROM AUTHOR]

This review presents an insight into our current knowledge of the atmospheres of the planets Venus, Mars, Jupiter, Saturn, Uranus and Neptune, the satellite Titan, and those of exoplanets. It deals with the thermal structure, aerosol properties (hazes and clouds, dust in the case of Mars), chemical composition, global winds, and selected dynamical phenomena in these objects. Our understanding of atmospheres is greatly benefitting from the discovery in the last 3 decades of thousands of exoplanets. The exoplanet properties span a broad range of conditions, and it is fair to expect as much variety for their atmospheres. This complexity is driving unprecedented investigations of the atmospheres, where those of the solar systems bodies are the obvious reference. We are witnessing a significant transfer of knowledge in both directions between the investigations dedicated to Solar System and exoplanet atmospheres, and there are reasons to think that this exchange will intensity in the future. We identify and select a list of research subjects that can be conducted at optical and infrared wavelengths with future and currently available ground-based and space-based telescopes, but excluding those from the space missions to solar system bodies. [ABSTRACT FROM AUTHOR]

Though enjoying complete intellectual and financial independence during the first half century of its existence, Lowell Observatory was forced to change its model after World War II, as science itself increasingly morphed into 'Big Science'. The first major source of outside funding in the Observatory's history was the US Weather Bureau, which supported a project to understand weather on a planetary scale by studying weather on Mars and Jupiter and--more enduringly--to record possible variations of solar irradiance. The latter was a longstanding problem which had occupied scientists such as Charles Greeley Abbot at the Smithsonian Astrophysical Observatory for decades, and had so far led to inconclusive results. At Lowell, it was to be approached by an innovative, if indirect, method involving the monitoring of changes of brightness in sunlight reflected from the cloudy atmospheres of distant Uranus and Neptune--a method whose time had just come, as photoelectric photometry had only just developed to the point where its implementation was feasible. Even so, it required a very high level of specialized knowledge and skill to be successful, and the Observatory was fortunate in recruiting young Harold L. Johnson, who was the best person possible for the job, to devise the instrumentation and design as well as provide overall supervision to the project from its inception until 1959 when he left Lowell. After his departure, the project, employing his experimental design, continued under the directorship of John S. Hall, mainly through the efforts of two Polish astronomers, K. Serkowski and M. Jerzykiewicz, who in 1966 concluded that, though the measures of Uranus could not be relied on owing to its uncertain oblateness, the detected variations of brightness of Neptune might be real, and if so, could be due either to changes in Neptune's atmosphere or to variations of the Sun. Air Force funding ran out in 1966. However, through the advocacy of climatologist J. Murray Mitchell Jr, the project was revived in 1971, with Saturn's large satellite Titan as an additional target. Jerzykiewicz returned to Lowell for two years before going back to Poland, whereupon he turned the project over in 1973 to G. Wesley Lockwood. The latter continued the observations of Uranus, Neptune and Titan until 2016, logging in addition atmospheric extinction data through two global volcanic episodes, El Chich'n and Pinatubo. With the advent of the solar satellite era after 1980, when more direct methods of determining solar irradiance became available, the planetary observations increasingly adopted as their new goal the monitoring of planetary seasonal variability. An on-again, off-again anti-correlation of Neptune's brightness with the sunspot number was suspected at Lowell but not finally and definitively established as a Sun-Neptune planetary weather effect until Berkeley scientists did so in 2023. However, probably the most important discovery made during the long-running Lowell programme was a serendipitous one. From the monitoring of solar-type stars originally included as standards of comparison for the planetary brightness measures, it was found that the brightness of some of these stars varied considerably more than the Sun does. Thus, as a byproduct of the Lowell project, a new vigorous area of ongoing research was established that continues to the present day. [ABSTRACT FROM AUTHOR]

The article discusses the concept of "analog environments" when searching for life beyond Earth. These environments are similar to those found on other planets or moons in our solar system and are often inhabited by extremophile lifeforms. Examples of analog environments include the Antarctic desert and dry valleys, which are similar to the cold and arid conditions on Mars, and Rio Tinto in Spain, which has rocks and soil rich in iron and acidity like Mars. Other analog environments mentioned are Lake Vostok in Antarctica, which is analogous to Jupiter's moon Europa, and the La Brea Tar Pits in California, which resemble the surface of Saturn's largest moon, Titan. The article emphasizes that while these analog environments provide promising places to look for life, they do not provide actual proof of its existence. [Extracted from the article]

A mathematical model is proposed for the origin of Saturn's dense (visible) rings, which has been a mystery for 400 years since Galileo saw them in 1610. Despite the technological perfection of the Cassini probe, which explored the Saturn system in 2004‒2017, the mission did not receive a final answer to this question. The available gravitational models cannot explain the origin of the stable disk of rings at the equator of the planet, but they can answer the question of where the ice in the rings came from. Therefore, we have added the action of the Saturn's magnetic field to consideration. We study the motion of ice particles within the Roche limit that could have formed as a result of the collision of two moons or the destruction of a Titan-sized body or Saturn's satellite. The problem of motion of a diamagnetic particle in the Saturn's gravitational and magnetic fields is solved. It is shown that, as a result of motion, diamagnetic ice particles form a disk system of rings on the magnetic equator of the planet. The effect of the Saturn's magnetic field (the Tchernyi‒Kapranov effect) is manifested in the magnetic anisotropic accretion of diamagnetic ice particles, which form a disk of rings, and the subsequent stabilization of the entire system of dense rings occurs. The solution of the problem begins with the determination of the magnetization and potential energy of a spherical diamagnetic particle in a magnetic field. We have derived an equation that relates the permeability of a diamagnet to its magnetization, which is an analogue of the Clausius‒Mossotti relation for a dielectric. It is used to study the dynamics of motion of a diamagnetic particle in the Saturn's gravitational and magnetic fields. Next, we solve the problem of a single magnetized sphere and a spherical particle among identical diamagnetic particles scattered in a disk-shaped structure. Differential equations of collisionless motion of diamagnetic particles in the Saturn's gravitational and magnetic fields are derived. A special, physically justified approximation of these equations is analytically solved. It suggests that the superposition of the gravitational and magnetic fields acting on a diamagnetic ice particle can explain the stability of Saturn's dense rings in the Saturn's equatorial plane. Due to this fact, the role of magnetism in stabilizing rings of other planets turns out to be universal. [ABSTRACT FROM AUTHOR]

Gravitational microlensing is a powerful method for detecting and characterizing free-floating planetary-mass objects (FFPs). FFPs could have exomoons rotating them. In this work, we study the probability of realizing these systems (i.e. free-floating moon-planet ones) through microlensing observations. These systems make mostly close caustic configurations with a considerable finite-source effect. We investigate finite-source microlensing light curves owing to free-floating moon-planet systems. We conclude that crossing planetary caustics causes an extensive extra peak at light curves' wing that only changes its width if the source star does not cross the central caustic. If the source trajectory is normal to the moon-planet axis, the moon-induced perturbation has a symmetric shape with respect to the magnification peak, and its light curve is similar to a single-lens one with a higher finite-source effect. We evaluate the Roman efficiency for realizing moon-induced perturbations, which is |$\left[0.002-0.094\right]\ \mathrm{ per\, cent}$| by assuming a log-uniform distribution for moon-planet mass ratio in the range ∈ [ −9,   −2]. The highest detection efficiency (i.e. |$\simeq 0.094~{{\ \rm per\ cent}}$|⁠) happens for Saturn-mass planets when moon-planet distance is ∼43 R p, where R p is the Saturn radius. Enhancing planetary mass extends the event's time-scale and decreases the finite-source effect, but it reduces the projected moon-planet distance normalized to the Einstein radius s (R E) which in turn decreases the size of planetary caustics and takes them away from the host planet's position in close caustic configurations. [ABSTRACT FROM AUTHOR]

This type of sand, ironically, is not the type of sand found in the desert country of Saudi Arabia, which must import sand for construction projects. Sand is one of those things that seems to get into everything (see Figure 1), but what exactly is sand? The source or origin of the type of sand used may be from natural sources such as the beds of rivers, the seafloor, the ground (pit sand), or manufactured sand. Sand is basically the most weathering resistant mineral fragments making up a rock eventually weathered into sand size particles. [Extracted from the article]

In response to ESA's "Voyage 2050" announcement of opportunity, we propose an ambitious L-class mission to explore one of the most exciting bodies in the Solar System, Saturn's largest moon Titan. Titan, a "world with two oceans", is an organic-rich body with interior-surface-atmosphere interactions that are comparable in complexity to the Earth. Titan is also one of the few places in the Solar System with habitability potential. Titan's remarkable nature was only partly revealed by the Cassini-Huygens mission and still holds mysteries requiring a complete exploration using a variety of vehicles and instruments. The proposed mission concept POSEIDON (Titan POlar Scout/orbitEr and In situ lake lander DrONe explorer) would perform joint orbital and in situ investigations of Titan. It is designed to build on and exceed the scope and scientific/technological accomplishments of Cassini-Huygens, exploring Titan in ways that were not previously possible, in particular through full close-up and in situ coverage over long periods of time. In the proposed mission architecture, POSEIDON consists of two major elements: a spacecraft with a large set of instruments that would orbit Titan, preferably in a low-eccentricity polar orbit, and a suite of in situ investigation components, i.e. a lake lander, a "heavy" drone (possibly amphibious) and/or a fleet of mini-drones, dedicated to the exploration of the polar regions. The ideal arrival time at Titan would be slightly before the next northern Spring equinox (2039), as equinoxes are the most active periods to monitor still largely unknown atmospheric and surface seasonal changes. The exploration of Titan's northern latitudes with an orbiter and in situ element(s) would be highly complementary in terms of timing (with possible mission timing overlap), locations, and science goals with the upcoming NASA New Frontiers Dragonfly mission that will provide in situ exploration of Titan's equatorial regions, in the mid-2030s. [ABSTRACT FROM AUTHOR]

Some of the major discoveries of the recent Cassini-Huygens mission have put Titan and Enceladus firmly on the Solar System map. The mission has revolutionised our view of Solar System satellites, arguably matching their scientific importance with that of their host planet. While Cassini-Huygens has made big surprises in revealing Titan's organically rich environment and Enceladus' cryovolcanism, the mission's success naturally leads us to further probe these findings. We advocate the acknowledgement of Titan and Enceladus science as highly relevant to ESA's long-term roadmap, as logical follow-on to Cassini-Huygens. In this White Paper, we will outline important science questions regarding these satellites and identify the science themes we recommend ESA cover during the Voyage 2050 planning cycle. Addressing these science themes would make major advancements to the present knowledge we have about the Solar System, its formation, evolution, and likelihood that other habitable environments exist outside the Earth's biosphere. [ABSTRACT FROM AUTHOR]

This study evaluates the efficacy of current satellite observing systems to detect methane point sources from typical oil and gas production (O&G) facilities using a novel very high-resolution methane concentration dataset generated using a microscale model. Transport and dispersion of typical methane emissions from seven well pads were simulated and the column enhancements for pseudo satellite pixel sizes of 3, 1, and 0.05 km were examined every second of the 2-h simulations (7200 realizations). The detectability of plumes increased with a pixel resolution, but two orders of magnitude change in emission rates at the surface results only in about 0.4%, 1.6%, and 47.8% enhancement in the pseudo-satellite retrieved methane column at 3, 1, and 0.05 km, respectively. Average methane emission rates estimated by employing the integrated mass enhancement (IME) method to column enhancements at 0.05 km showed an underestimation of the mean emissions by 0.2–6.4%. We show that IME derived satellite-based inversions of methane emissions work well for large persistent emission sources (e.g., super emitters), however, the method is ill-suited to resolve short-term emission fluctuations (< 20 min) in typical well site emissions due to the limitations in satellite detection limits, precision, overpass timing, and pixel resolution. [ABSTRACT FROM AUTHOR]

We aim to establish a rough first prospect on the potential of certain biorelevant solvents (water, ammonia, and methane) being present in liquid form inside the uppermost few meters of several modeled rocky and icy surfaces of hypothetical bodies orbiting active galactic nuclei (AGNs) and investigate under which constraints this might occur. For this, we adjust and average X-ray spectra from a sample of 20 Type-1 Seyfert galaxies to calculate the mean snowline of the sample used. We then vary the hypothetical body's orbit between 10% and 100% of the snowline radius and calculate a sub-surface attenuation within four different model surface compositions for each. We then use this as a continuous source term for a thermal model. Example bodies are systematically investigated with sizes between 1/30 and 20 earth radii, with further variations also considered (such as possible bound rotation), to end up with a perspective of solvent phases under a wide slew of different conditions. We find that liquid solvents are possible under a multitude of parameters, with temperature being the main constraint to liquid water whereas body size and pressure are the main constraint to liquid methane and ammonia. [ABSTRACT FROM AUTHOR]

The article titled "What's Up in the Sky? June/July 2024" provides information on the visibility and positions of various celestial objects during the months of June and July. It mentions that Mercury is barely visible in the dawn sky, Venus is difficult to observe, Mars is low in the morning sky, Jupiter emerges into the morning twilight, Saturn appears fainter than usual, Uranus and Neptune are not easily visible, and dwarf planets Ceres and Pluto are visible with telescopes. The article also mentions the presence of Comet C/2023 A3 (Tsuchinshan-ATLAS) in the evening sky. The Sky Calendar for June and July is provided, highlighting specific events such as planetary conjunctions, moon transits, and meteor showers. [Extracted from the article]

Six of the solar system planets have 150 confirmed moons (Earth—1, Mars—2, Jupiter—53, Saturn—53, Uranus—27, Neptune—14) and seven of them (Ganymede, Titan, Callisto, Io, the Moon, Europa, Triton) have masses >0.001  |$M_\oplus$|⁠. However, no exomoons have yet been discovered despite the successful detection of ∼5000 exoplanets. We can infer, based on the solar system planets, that these exoplanets are capable of hosting one or more exomoons. In this paper, we study the possible existence of hypothetical Earth-mass and Luna-mass moons orbiting the Jupiter-mass planet, Laligurans (HD 100777b) in the Sagarmatha (HD 100777) star system by means of orbital stability. We apply long-term orbital integrations and the MEGNO (mean exponential growth of nearby orbits) chaos indicator to study the orbital stability of the moons and predict a phase-space region comprising periodic, chaotic, and unstable orbits. The phase spaces primarily constitute the moon's semimajor axis, which extends from the host planet's Roche radius to the Hill radius, and full range of eccentricity. Specific points are picked from three different regions of the MEGNO map and run as single-orbit integration for up to 10 billion periods of the innermost orbit. Furthermore, the lifetime and maximum eccentricity maps are generated from the direct integration to inspect the stable and unstable orbital configurations. The analyses of these maps, with the aid of time-series plots, show that both moons maintain stable orbits in the low-eccentricity regime and semimajor axis between the Roche limit and 28.4% of the Hill radius of the planet. [ABSTRACT FROM AUTHOR]

• The studied spectral region near 3.3 μm of the ethylene spectrum is of importance to derive its accurate concentration in the atmosphere. • A list of 3328 assignments was determined for four vibrational bands using the tensorial formalism through 79 adjusted parameters for four vibrational bands. • About 2190 line intensities are adjusted by adjusting 14 parameters. • Cross sections are computed and compared with literature. • A new line list of calculated lines in the studied spectral region has been added to the ECaSDa and to the HITRAN databases. Ethylene (or ethene) is a natural gas compound present in our atmosphere but also in the atmospheres of outer solar system planets such as Jupiter, Saturn, Uranus, Neptune and Saturn's moon Titan. However, a better knowledge of spectroscopic parameters is needed for this molecule in order to detect its presence and/or to derive its accurate concentration. We present here a detailed analysis and modeling of the strongly absorbing ν 9 and ν 11 fundamental bands in the 3.3 µ m region. Due to the complexity of the observed spectrum, we have built a polyad scheme taking into account some fundamental bands previously analyzed thanks to the tensorial formalism developed in Dijon for asymmetric-top molecules. A four polyad system has been settled and the last P 3 polyad contains four vibrational states: ν 9 , ν 11 , ν 2 + ν 12 and 2 ν 10 + ν 12. A first frequency analysis has been performed, leading to 3328 assignments with a root mean square of 5. 927 × 10−3 cm−1 and a standard deviation of 1. 965 using 88 adjusted parameters, and we have also adjusted line intensities of 2190 lines by adjusting 14 parameters with an overall Root-Mean-Square (RMS) deviation of about 3.77 %. A new linelist of calculated lines in the 2900−3300 cm−1 region has been added to the ECaSDa and we plan to integrate it to the HITRAN database. [ABSTRACT FROM AUTHOR]