![Retrieved temperature, mixing ratios, and haze parameters from all three retrieval set ups. Left: Retrieved volume mixing ratios for all three retrieval cases shown at the approximate depth of the haze layer. Right: Haze opacity in dashed lines and temperature in solid lines as a function of pressure and altitude. Where available we show the Teanby et al. (2006) mixing ratios and temperature profile. Despite varying assumptions and haze schemes, all retrievals indicate a haze layer in approximately the same pressure location. Note that the POSEIDON haze location is inferred from the pressure contribution functions and is shown as a shaded region. - [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Piercing-through.png?resize=1200%2C710&ssl=1)
[astro-ph.EP] As we enter a new era of using JWST to characterize exoplanet atmospheres, a top priority is defining observational needs and parameters in the search for life on an […]
astro-ph.EP
![Schematic showing the thermal and atmospheric escape evolution of two interpretations of sub-Neptune interiors. In a standard planetary model, a silicate interior is distinct from a hydrogen-rich envelope. As the planet contracts, hydrogen is removed from the upper atmosphere via stellar heating, and the interior-envelope boundary does not significantly contract with time. The temperature at this interface can reach of order ∼ 10, 000 K at early ages. In the miscible model, the interior-envelope boundary is defined by a binodal surface, which delineates regions in which hydrogen and silicate are miscible or immiscible. The temperature at the binodal surface does not change significantly with time. The radial position of the binodal surface contracts with time, exsolving hydrogen into the base of the envelope, while hydrogen is also removed from the top of the upper atmosphere.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Testing-the.png?resize=1200%2C716&ssl=1)
Posted inExoplanets, -moons, -comets
Testing The Prevalence Of Hydrogen-silicate Miscibility In Young Sub-Neptunes
[astro-ph.EP] Hydrogen-silicate miscibility can significantly alter the interior structure and thermal evolution of sub-Neptunes. We consider the interplay between this miscibility and stellar-driven atmospheric escape.
Posted inExoplanets, -moons, -comets
The Mid-Infrared Transmission Spectrum of the Temperate Sub-Neptune TOI-270 d
[astro-ph.EP] Observations of temperate sub-Neptunes with JWST have ushered in a new era for atmospheric characterization of small exoplanets.
![[LEFT] Evolution of the fiducial full 2D simulation. The simulation has run for ∼ 4 Myr; line opacity increases with time in intervals of 0.4 Myr. The top row shows the surface densities of dust (ice included), ice and vapour, whilst the second row shows the mid-plane temperature. The small noncontinuous deviations in the surface density appear due to integration over the tightly-constrained, discontinuous vertical structure of the ice. [RIGHT] Spatial distributions of CO ice and vapour density in the full 2D fiducial simulation. Temperature contours (in K) are over-plotted for reference. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/CO-snow-lines.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
CO Snow Lines Are Stabilised By The Vertical Transport Of Volatiles
[astro-ph.EP] Volatile evolution in protoplanetary discs determines the compositional evolution of forming planets. Below their sublimation temperatures, volatiles freeze out from the vapour phase onto dust grains in the disc […]
![[TOP] Example observations of (2060) Chiron for survey/telescopes (left) ATLAS, (middle) ZTF, and (right) LCO/LOOK. [BOTTOM] Example observations of 103P/Hartley 2 for survey/telescopes (left) ATLAS, (middle) ZTF, and (right) LCO/LOOK. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Multi-year.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
Multi-year Ground-Based Survey Photometry of Active Comet 103P/Hartley 2 and Centaur (2060) Chiron: A Tale of Two Comets in the Pre-LSST Era
[astro-ph.EP] Comets and Centaurs trace the evolution of trans-Neptunian objects (TNOs) into the inner solar system.
Posted inComets and Asteroids
The Dust Mineralogy of Interstellar Comet 3I/ATLAS from JWST/MIRI Observations
[astro-ph.EP] We present the first spectroscopic mineralogical analysis of the dust coma of an interstellar object (ISO) from JWST mid-infrared spectroscopy of 3I/ATLAS (3I).
Posted inExoplanets, -moons, -comets
Characterising Transiting Exoplanets At Long Orbital Period: Lessons Learned For PLATO From 10 Years Of Monitoring The HIP41378 System
[astro-ph.EP] The upcoming launch of the PLATO mission will open a new area of exoplanetary research by probing transiting exoplanets at long orbital periods around bright stars.
Posted inAstrochemistry
Implications Of Self-consistent H2O Ice Optical Constants On Radiative Transfer Models Of Disks
[astro-ph.EP] Interstellar water (H2O) ice exhibits significantly varied profiles over its spectral features with temperature and thermal history.
Posted inExoplanets, -moons, -comets
The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c
[astro-ph.EP] Hot Neptunes are close-in exoplanets that occupy a sparsely populated region of parameter space known as the “hot-Neptune desert”.
Posted inUncategorized
An Agnostic Machine Learning Model of Photosynthetic Habitability
The search for exoplanet biosignatures is guided by whether planetary environments can sustain photosynthesis.