![The figure illustrates the four main phases of low-mass star formation: from the gravitational collapse of the natal core of gas and dust (Prestellar Core), to the main accretion phase (Class 0/I protostar, age ∼104 -105 yr), followed by the protostar and its surrounding protoplanetary disk (Class I/II, age ∼105 -106 yr), and finally the revealed planetary system after the disk has dispersed (Class III, age ∼107 yr). Typical spatial and timescales are indicated for each stage. Generated with Google Gemini 3 Flash and modified. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Cradle-of-Life.png?resize=1200%2C714&ssl=1)
[astro-ph.SR] This chapter provides an overview of the different science cases covered by the “Cradle of Life” working group, which aims to leverage the capabilities of the Square Kilometre Array […]
Atmospheres, Climate, Weather
![Reflation events (red) occur across a range of ages and with different magnitudes across the evolution of irradiated super-Earths. The plot shows the normalised bulk density evolution of individual simulations, versus the time elapsed since planet formation. The red lines indicate cases where a reflation event occurs, while blue lines indicate those where it does not occur. The evolution tracks that end with a dot indicate the planet has reached an airless state and complete atmospheric erosion by hydrodynamic escape has taken place. The evolution of the two select cases for Figure 1 are highlighted and denoted with a R and D. These cases illustrate in more detail a representative reflation (red) and deflation case (blue). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Reflation.png?resize=1200%2C717&ssl=1)
Posted inAstrogeology
Reflation: Redox-driven Atmospheric Inflation As Tracer Of Super-Earth Geochemistry
[astro-ph.EP] We demonstrate that the redox-sensitivity of mantle outgassing can trigger transient episodes of atmospheric re-inflation in highly irradiated and geochemically-reduced super-Earths, a mechanism we term reflation.
![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)
Posted inExoplanets, -moons, -comets
Piercing Through The Haze: Characterizing Titan-like Terrestrial Exoplanets With JWST
[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 […]
![Averages over 100 trials of Siberian Traps injection scenario on a 31× 31 grid in the (fp, θ) parameter space. Mean number of DIC peaks (left), mean maximum DIC jump (top right), and mean time to return to equilibrium after end of injection phases (bottom right) are shown. The letters in the left panel correspond to parameters used in the example trials shown in Figure 10. -- [physics.ao-ph]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Modeling-the-response.png?resize=1200%2C720&ssl=1)
Posted inAtmospheres, Climate, Weather
Modeling The Response Of Earth’s Marine Carbon Cycle To Extreme CO2 Injection Events
[physics.ao-ph] We explore how the response of a conceptual model of the marine carbon cycle depends on the way in which carbon is injected from the atmosphere.
Posted inHabitable Zones
When Stabilizing Feedbacks Wreak Havoc In Habitable Planets: Chaos At The Freezing Point In A Four-Feedback Climate Model
[astro-ph.EP] The long-term habitability of Earth-like planets is governed by the balance of positive and negative climate feedbacks that regulate surface temperature and atmospheric composition.
![Detection map of our sample (excluding system with inner giant planets). Red dots represent the known planets, including the new candidates discussed in Section 6.3. [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/The-GAPS-Programme-.png?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
The GAPS Programme with HARPS-N at TNG LXXVII. Occurrence Rates Of Small Close-in Planets In The Presence Of Cold Jupiters
[astro-ph.EP] Context. The architecture of our Solar System, with inner small planets (ISPs) and outer giants, may or may not be common. Understanding whether a correlation exists between ISPs and […]
Posted inExoplanets, -moons, -comets
Distant Exoplanets May Be Hiding Water Beyond Webb Telescope’s Reach, Study Finds
[University of Chicago] The planets that appear most common in the universe could have a lot of water—but it could be hiding where telescopes can’t detect it, according to a […]
Posted inSETI & Technosignatures
Decolonizing Technosignatures: Reimagining Technosignatures Through An Indigenist Lens
[astro-ph.IM] There exist numerous proposals for potential technosignatures that we can search for, but they all tend to be deviations from possible naturally occurring signals. That is, technosignatures tend to […]
![Cartoon illustrating the effect of the runaway greenhouse transition on atmospheric composition for two rocky planets with identical He, H2O and CO2 inventories. With a thin He atmosphere, planets below the runaway greenhouse limit (right) will have He-rich upper atmospheres and may support surface liquid water. For planets inside the inner edge of the habitable zone (left), H2O from liquid water oceans and CO2 from carbonates are transported into the atmosphere, dramatically decreasing the scale height and making the transit spectrum of the planet flatter. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Climates-of-temperate.png?resize=1200%2C720&ssl=1)
Posted inExoplanets, -moons, -comets
Climates Of Temperate Rocky Planets With He-dominated Atmospheres
[astro-ph.EP] We present radiative-convective modeling of rocky exoplanets with He-dominated atmospheres and low envelope mass fractions. Helium has a steeper adiabatic temperature profile than N2 and H2 as it has […]
![Best-fitting spectrum and atmospheric properties of WD 1856 b. a. Spectral decomposition illustrating the model components required to explain WD 1856 b’s JWST transmission spectrum (FIREFLy reduction; orange circles with 1 σ error bars). The best-fitting model (black curve) contains absorption from multiple CH4 features (purple shading), H2 + He continuum absorption (dark grey shading), and tentative evidence of C2H6 near 3.4 µm (brown shading) and PH3 near 4.3 µm (orange shading). Aerosol continuum opacity (silver shading) blocks thermal emission from the deep atmosphere in windows between CH4 bands, obscuring the ‘negative spikes’ that would otherwise be observed near 0.7 µm, 2.9 µm, and longwards of 4.0 µm for a clear atmosphere. The best-fitting model without nightside thermal emission (blue dashed curve) cannot explain the significantly lower transit depths longwards of 3.5 µm. b. Retrieved atmospheric properties, planetary mass, and aerosol properties from WD 1856 b’s JWST transmission spectrum for the FIREFLy (orange histograms) and Juniper (green histograms) data reductions. The median (solid line) and 1 σ credible intervals for each parameter (dashed lines) are overlaid. c. Residuals between the data and best-fitting model. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/07/Aerosols.png?resize=1200%2C719&ssl=1)
Posted inAtmospheres, Climate, Weather
Aerosols And Hydrocarbons In The Atmosphere Of A White Dwarf Planet
[astro-ph.EP] Most stars, including our Sun, will one day evolve into red giants and, subsequently, white dwarfs. Several planet candidates have recently been identified orbiting white dwarfs, demonstrating that planets […]