[astro-ph.EP] The PLATO mission will observe its first long-pointing field, LOPS2 (Long-duration Observation Phase, South field), for at least two years, bringing the habitable zones (HZ) of its M-dwarf sample […]
Habitable Zone
Posted inIcy Worlds
Amplified Cooling Of Snowball Earth From A Salt-albedo Feedback
[Climate of the Past] It is believed that the atmospheric circulation on Snowball Earth produced a net ablation zone exposing bare sea ice.
![Dereddened Gaia CMD with PARSEC isochrones overplotted. Black points show Gaia DR3 stars corrected for extinction and reddening using band-specific coefficients. Solid curves show isochrones spanning ages from 1 to 13 Gyr at the reference metallicity. The dotted curves highlight 1 Gyr isochrones computed at the lower (-0.4 dex) and upper (+0.4 dex) metallicity values in the sample, illustrating the range of CMD permitted by the observed metallicity distribution. This comparison demonstrates the impact of metallicity on isochrone placement relative to the data. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Precise.png?resize=1200%2C718&ssl=1)
Posted inExoplanets, -moons, -comets
Precise Stellar Age Constraints and Habitable Zone Evolution in Exoplanet Systems
[astro-ph.EP] Accurate stellar ages are fundamental to interpreting the evolutionary histories of habitable zone (HZ) planets. Because stellar luminosity evolves over time, HZ boundaries migrate outward, meaning that present-day HZ […]
Posted inApps - Games
pyEDITH: The Coronagraphic Exposure Time Calculator For The Habitable Worlds Observatory
[astro-ph.IM] To support the development of next-generation missions for the search and characterization of habitable planets, high-fidelity tools for astrophysical and instrumental noise simulations are needed.
Posted inExtremeophiles and Extreme Environments
Cultivation Of Halophilic Archaea In Shallow Subsurface Martian Conditions Has Implications For Extant Life On Mars
[biorxiv.org] The present-day martian surface is generally considered inhospitable to life because of low atmospheric pressure, intense surface radiation, global desiccation, and oxidizing chemistry which has been increasing since the […]
![Cumulative oxygen loss for planets at the habitable zone of each sample star over 1 Gyr, assuming constant stellar XUV flux at the HZ and no replenishment of oxygen. The curves are calculated using the energy-limited O2 loss prescription from V. S. Airapetian et al. 2017. Colored lines show individual stars, with solid segments representing the earliest ages (for stars with age ranges) and dashed segments extending beyond the minimum age. The black solid line shows the solar reference. Horizontal lines indicate the present-day Earth atmospheric O2 content (∼0.2 bars; dotted) and the total mass of Earth’s oceans (∼240 bars; dashed), providing reference levels for planetary habitability. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Panchromatic.png?resize=1200%2C720&ssl=1)
Posted inHabitable Zones
Panchromatic Spectra of Nearby Low-mass and Sun-like Stars with Directly Imageable Habitable Zones
[astro-ph.SR] Characterizing the high-energy radiation environments of stars plays a critical role in determining which systems’ planets are capable of retaining atmospheres and sustaining habitable conditions.
![Surface temperature of the 22 exoplanets in an aquaplanet configuration. Obliquity and eccentricity are set to zero, and all are tidally locked with Earth-like atmospheric chemistry and pressure. Level lines correspond to the temperatures of 223.15, 273.15, and 323.15 K. White lines indicate the terminator, that is, the boundary between the illuminated and the dark sides of a planet. Black dots indicate the prevalence of sea ice (ice fraction larger than 0.5). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Assessing-1.png?resize=1200%2C717&ssl=1)
Posted inHabitable Zones
Assessing The Climate And Habitability Of Tidally Locked Rocky Exoplanets
[astro-ph.EP] Tidally locked exoplanets orbiting M dwarf stars are prime targets in the search for habitable worlds, yet their complex climate dynamics challenge conventional models of habitability.
Posted inExoplanets, -moons, -comets
An Evolving Cosmic Shoreline and Sandbar Bounding the Rocky Airless Valley
[astro-ph.EP] Recent JWST observations challenge the traditional ‘cosmic shoreline’ from both sides, revealing thick volatile atmospheres on the hottest close-in ‘lava worlds,’ where irradiation should drive the most extreme escape, […]
![Earth biosignatures through time and their reflected light spectra. The left subplot shows estimates of Earth’s bulk atmospheric composition through time (advancing from top to bottom), and the figures on the right show the corresponding reflected light spectra considered in this study. Key absorption features for biosignature gases (O3, O2, CH4) and suggested long- and short-wavelength cutoffs are highlighted (as discussed further in Sections 3 and 4). Adapted from National Academies of Sciences, Engineering, and Medicine (2021) and LUVOIR and HabEx Final Reports (LUVOIR Team, 2019; Gaudi et al., 2020). -- [Astrobiology (Journal)]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Wavelength.png?resize=1200%2C719&ssl=1)
Posted inBiosignatures & Paleobiology
Wavelength Requirements for Life Detection via Reflected Light Spectroscopy of Rocky Exoplanets
[Astrobiology (Journal)] Searching for signs of life is a primary goal of the Habitable Worlds Observatory (HWO). However, merely detecting oxygen, methane, or other widely discussed biosignatures is insufficient evidence […]
Posted inExoplanets, -moons, -comets
Transit Searches for Habitable-Zone Exoplanets with Artificial Intelligence
[astro-ph.EP]. Searching for Earth-sized planets in stellar habitable zones ultimately means finding a small number of very shallow, widely separated transits in noisy light curves.