[astro-ph.EP] Giant planets orbiting low-mass M dwarfs challenge current planet formation theories, which predict that such planets are unlikely to form. Characterizing their atmospheres can provide key insight into their […]
Atmospheres, Climate, Weather
Posted inAtmospheres, Climate, Weather
MarsCast: Transfer Learning Of AI Weather Foundation Models To Planetary Atmospheres
[astro-ph.EP] We investigate the transferability of Earth weather foundation models to planetary atmospheres by adapting the GraphCast graph neural weather forecasting model to Mars. While GraphCast achieves state-of-the-art performance for […]
Posted inJupiter
Self-consistent 1D Modelling Of Jupiter’s Upper Atmosphere As An Exoplanet Analogue
[astro-ph.EP] Jupiter’s upper atmosphere provides a real-world laboratory for validating first-principles models of giant gaseous exoplanets and for constraining the key physical processes that govern them.
![Average ion velocity and magnetic field distributions near the ICB. (A) The center-of-mass velocity of heavy ions in the XZMSE plane, averaged over −1 RM < YMSE < 1 RM. (B) Proton velocity. (C) Velocity shear between protons and heavy ions. (D) Magnetic field strength. (E) Angle between the magnetic field and the X�⃗ MSEin the YZMSE plane, averaged over −1.5 RM < XMSE < 0.5 RM. Black arrows in (A) to (C) indicate velocity directions. Black curves in (A) to (D) mark the nominal locations of the bow shock and ICB. The black shaded sphere in (E) denotes the planetary shadow. -- [physics.space-ph]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Simultaneous.png?resize=1200%2C720&ssl=1)
Posted inSpace Weather & Heliophysics
Simultaneous Mars-orbit Observations Reveal Kelvin-Helmholtz Instability-driven Bulk Atmospheric Ion Escape
[physics.space-ph] Atmospheric ion escape driven by the solar wind is a key process controlling the long-term loss of the Martian atmosphere. Localized plasma clouds can carry substantial fluxes of planetary […]
![Life 2.0 mission concept and simulated biosignature spectroscopy. The distributed array observes a common target with many one-meter telescope modules. The example spectra illustrate UV-optical atmospheric signatures and the simulated recovery of O₃, O₂, and H₂O after calibrated spectral co-addition. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Life-2.0.jpg?resize=1200%2C719&ssl=1)
Posted inBiosignatures & Paleobiology
Life 2.0: A Scalable Distributed Space-Telescope Array For Biosignature Spectroscopy
[astro-ph.IM] Answering the question “Are we alone?” requires atmospheric spectroscopy of nearby terrestrial planets. For an Earth–Sun analog, even the strongest transmission signals are expected to be of order 1 […]
![[LEFT]: Schematic of the star–planet–observer geometry defining the phase angle α, measured between the star–planet and planet–observer directions. The hemisphere of the planet facing the star is fully illuminated (gold) at all times, while the opposite hemisphere remains in shadow. The observer sees only the portion of the illuminated hemisphere that is visible at a given α, with full illumination visible only at α = 0◦. [RIGHT]: Illustration of planetary phases along an edge-on orbit, with the star at the center and the observer direction indicated below the orbit. Although the star-facing hemisphere remains illuminated throughout the orbit, the visible fraction of this hemisphere changes with phase angle. Full phase occurs at α = 0◦, quadrature at α = 90◦, and new phase at α = 180 , with gibbous and crescent phases spanning the intermediate ranges. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Impact.png?resize=1200%2C714&ssl=1)
Posted inAstronomy & Telescopes
The Impact of Planetary Phase Functions On Exo-Earth Detectability With EXOSIMS
[astro-ph.EP] The under-development NASA Habitable Worlds Observatory (HWO) aims to provide breakthroughs in exoplanet science, yet the most effective approaches to modeling the detection and characterization of potentially Earth-like worlds […]
![Latitude-longitude maps of column-integrated water clouds (panels a, b and c), outgoing longwave radiation (OLR, panels d, e and f) and albedo at the top of the atmosphere (TOA albedo, panels g, h and i) for Cases 2A, 2B and 2C. The variables are averaged over ∼50 orbits. The dashed white line on the albedo color bar corresponds to the surface albedo.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/A-broad.png?resize=1200%2C719&ssl=1)
Posted inExoplanets, -moons, -comets
A Broad Exploration Of Climate And Observability Of Close-in Rocky Exoplanets: Applications To Ross 128 b
[astro-ph.EP] VLT/RISTRETTO, ELT/ANDES and ELT/PCS will soon enable atmospheric characterization of non-transiting, small rocky exoplanets orbiting closer than the inner edge of the Habitable Zone around M dwarfs, combining high-contrast […]
![Physical and chemical gradients predicted to dictate habitability across depth in the martian subsurface. These include (1) constraints on water; although water activity (aw) gradients are not yet known for Mars, predicted liquid brine stability depends on primary ionic composition with perchlorate-rich brines transitioning into chloride- and sulfate-enriched brines with depth and temperature (Chevrier and Slank, 2024; Stevens and Cockell, 2023). It is important to note that porosity is expected to decrease with depth, which may also influence water availability, with any potential brines increasingly localized to pore spaces and fractures (Michalski et al., 2018). (2) Surface radiation exposure is expected to subside to lower background radionuclide decay around 3–5 m depth. (3) If liquid water is present at depth, chemotrophic microbial communities could utilize the products of water–rock interaction including inorganic electron donors/acceptors and simple abiotic organics. Image created using biorender.com.-- [Astrobiology (Journal)]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Life-Detection.png?resize=1200%2C719&ssl=1)
Posted inMars
Life Detection In The Martian Subsurface: Advancements In Microbial Metabolic Research Under Mars Laboratory And Field-Analog Conditions Since Viking
[Astrobiology (Journal)] Following the Viking experiments in 1976, many of the original inferences of biological metabolism have been replicated via abiotic mechanisms we now know are plausible on Mars’ surface.
![Pollux optical layout. The exact sequence in the optical path of the retractable polarimeters and fiber link connections of the OPT and NIR is still to be discussed and what shown here is not representative of the final configuration. -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Pollux.png?resize=1200%2C715&ssl=1)
Posted inExoplanets, -moons, -comets
Pollux: High-resolution Precision Spectroscopy And Polarimetry For The Habitable Worlds Observatory
[astro-ph.IM] Pollux is a high-resolution spectrograph and spectropolarimeter (R from 65000 to 100000) covering a spectral range from 100 nm to 1750 nm, proposed by a European consortium to equip […]
Posted inVenus
Development Of A Data Retrieval Algorithm For Venus Nephelometry In Preparation For The Rocket Lab Mission To Venus
[Science Direct] The Rocket Lab Mission to Venus (RLMV) will carry a single primary instrument, the Autofluorescence Nephelometer (AFN), to interpret atmospheric particle properties from light-scattering measurements. This process is […]