[astro-ph.EP]. Interpreting Enceladus’s past and present surface history and interior state remains challenging, owing to uncertain prescription of its impact bombardment history and limited interpretation of its crater statistics. Further […]
astro-ph.EP
![CI mass as a function of radial distance from the host star, for a continuum of solid surface densities. Over-plotted is the FI1 mass (𝑀¤ = 10−9 M⊙ yr−1 ) for a continuum of maximum Stokes numbers, as well as the MFI1 (opaque purple) and MFI2 (dashed red) masses and the PI mass (dotted black). The last three show no continuum of mass distributions, since we vary their initial mutual Hill spacing within the simulation. Thus, all initial simulations begin from the same mass distribution model, albeit with a different number of embryos at different spacings.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Effects-of-Pebble.png?resize=1200%2C715&ssl=1)
Posted inExoplanets, -moons, -comets
Effects Of Pebble Accretion Isolation Mass On Observable Exoplanet Properties
[astro-ph.EP] The Kepler Mission has discovered a plethora of planetary systems with super-Earth sized planets.
Posted inHabitable Zones
Planetary Stability and Long-Term Habitability in Nearby Stellar Binaries: 70 Oph, 36 Oph, γ Leo
[astro-ph.EP] Binary stars are common and have the potential to host habitable planets, which may reside in more complex habitable zones as compared to planets orbiting single stars.
Posted inComets and Asteroids
An Enriched Methane D/H Ratio in the Interstellar Object 3I/ATLAS
[astro-ph.EP]. Interstellar objects are interlopers from other planetary systems, and their volatile compositions provide a glimpse into planet formation around their host star.
Posted inPhobos
Infrared-to-visible Albedo Ratio Of Phobos: Comparison With Primitive Asteroids
[astro-ph.EP] Aims. The ratio between infrared and visible albedo, pIR/pV, provides a simple proxy for the spectral slope of asteroid surfaces between the visible and near-infrared wavelength ranges. The aim […]
![Top left: (pgas, Tgas) cross-section through the terminators of WASP-69 b, with the location of the CH4 quench point overlaid (light blue line). We define the CH4 quench level as the pressure where the absolute relative difference between the equilibrium and disequilibrium concentrations first exceeds 10−3. Top right: Column densities in the line-of-sight direction in the atmosphere of WASP-69 b for [M/H] = 1.0, and C/O = 0.55 for CH44. Bottom: The same as for CH4 but now for SO2 (left) and CO2 (right). The terminator pressure scale is used as a radius axis. The hotspot offset at 10−4 bars is reflected in the column density of SO2, with larger concentrations being formed on the evening terminator. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Chemical-Tracers.png?resize=1200%2C716&ssl=1)
Posted inExoplanets, -moons, -comets
Chemical Tracers For 3D Atmospheric Asymmetries On WASP-69 b
[astro-ph.EP] Warm giant exoplanets exhibit strong three-dimensional temperature contrasts that can significantly alter atmospheric chemistry through quenching and photochemistry, yet transmission spectra are commonly interpreted using one-dimensional, limb-averaged models. Such […]
Posted inVenus
Altered Cosmic Organics As Venus’ Ultraviolet Absorbers
[astro-ph.EP] Venus’ ultraviolet (UV) absorbers significantly contribute to the atmosphere’s energy budget. However, the composition of these absorbers remains a mystery.
![(a) Schematic of Europan ice-ocean system [related image in 11]. (b) Map of sea surface temperature (◦C) showing the transition between the temperature-stratified North Atlantic Ocean and the salt-stratified Arctic Ocean; (c) Potential temperature (left) and salinity (right) profiles with depth from location near the North Pole. Different water-mass characteristics are labeled. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/What-can.png?resize=1200%2C582&ssl=1)
Posted inWater/Hycean Worlds & Oceanography
What Can Planetary Ice Shells Teach Us about Ocean Mixing and Life, and Why Salt Matters
[astro-ph.EP] Past and present climates, both on Earth and in planetary systems, maintain ice covers with underlying oceans. This can range from sea ice in the Arctic Ocean to global […]
Posted inExoplanets, -moons, -comets
Atmospheric Diversity of Giant Planet Analogs from 3-5µm with SPHEREx
[astro-ph.EP]. The emergent spectra of giant planets peak at thermal infrared wavelengths (3-5um) and possess atmospheric features in this regime that trace carbon chemistry, vertical mixing, clouds, and composition.
Posted inAstrogeology
Setting The Stage: The Early History Of The Solar System
[astro-ph.EP] This article reviews the early history of our solar system from an astrobiological perspective and presents evidence from meteorites and astronomical observations. The purpose is to trace the formation […]