![Atmospheric and water loss of an Earth-like planet for three stellar systems: (e,f) M-dwarf (TRAPPIST-1) central habitable zone. The mass losses shown in a,b,c and d are after 6 Gyr of system integration. -- Full chart below [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Simulated-Effects.png?resize=1200%2C718&ssl=1)
[astro-ph.EP] Thousands of exoplanets have been discovered in recent decades, yet Earth remains the only known world with life.
space weather
![Contribution of a flare to the observed spectrum on anM-dwarf using a BT-Settl model spectrum (Allard 2014) -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Stellar-flares.png?resize=1200%2C714&ssl=1)
Posted inAriel Mission
Stellar Flares With Ariel: Detection Prospects And Impacts On Exoplanet Spectroscopy
[astro-ph.SR] Stellar flares are important tracers of magnetic activity and can significantly influence the characterization of exoplanet host stars by introducing time-dependent astrophysical variability.
![Atmospheric energy deposition profiles of GCRs and SEPs in the atmosphere of K2-18b for different magnetic field strengths. The profiles have been smoothed to improve visual clarity. For visibility, the deposited energy corresponding to B=300 ĀµT has been multiplied by a factor of 10. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Energy-.png?resize=1200%2C718&ssl=1)
Posted inSpace Weather & Heliophysics
Energy Deposition In Planetary And Exoplanetary Atmospheres Induced By Cosmic Rays
[astro-ph.EP] Cosmic rays can significantly alter the abundances of certain species in the upper layers of planetary atmospheres, especially in terms of their biosignatures. To fully understand the extent of […]
Posted inSpace Weather & Heliophysics
Cosmic Radiation at Flight Altitudes Rises When the Sun Is Less Active
[Hebrew University of Jerusalem]. Radiation from space is constantly entering Earthās atmosphere, but how much of it reaches the altitudes used by commercial aircraft depends not only on height and […]
![Panel (a): HR diagram of the OC members with detections. The blue solid line is the fitting results of MS. green dashed lines represent the upper and lower bounds of the MS fitted with a Ā±0.5 offset, and the red dashed line is the same sequence shifted upwards by 2. The color bars represent the stellar ages. Panel (b): HR diagram of the field stars with detections. Panel (c): The Galactic distribution of the selected sources from the detected OC members. Panel (d): The Galactic distribution of the selected sources from the detected field stars. -- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/09/Evolution-of.png?resize=1200%2C720&ssl=1)
Posted inHabitable Zones
Evolution of Stellar Activity and Habitable Zone (EATEN): III. X-ray Activity of Dwarfs in Open Clusters and Field Stars
[astro-ph.SR] Stellar X-ray emission serves as a direct diagnostic of coronal activity, which is fundamentally linked to coronal heating processes. It also strongly influences the atmospheres and long-term habitability of […]
Posted inOrigin & Evolution of Life
Auroral Belts As Magnetically Localized Reactors For Prebiotic Chemistry On Early Earth
[Biosystems] Most models of prebiotic chemistry emphasize globally distributed or widely acting energy sources, including ultraviolet radiation, lightning, impacts, and energetic particles.
![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 (ā¼0.2 bars; dotted) and the total mass of Earthās oceans (ā¼240 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.
Posted inSpace Weather & Heliophysics
Preparing For The Early eVolution Explorer: The Impact of Flare Temperature on Ozone Column Depth in Earth-Like Atmospheres
[astro-ph.EP] Atmospheric photochemical models incorporating the impacts of stellar flares often assume a ā¼9,000 K spectrum at ultraviolet-optical wavelengths.
![Normalized magnetospheric standoff distance rM/rpl as a function of the planetary magnetic field and the total stellar pressure for Modern Earth (left panel) and Early Earth (right panel) across the HZ of the host star. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-impact-of.png?resize=1200%2C714&ssl=1)
Posted inExoplanets, -moons, -comets
The Impact Of Tidal Locking On Earth-like Planetary Dynamos
[astro-ph.EP] We investigate how tidal locking affects the planetary dynamo and the magnetospheres of Earth-like planets orbiting the habitable zones of M dwarfs.
Posted inSpace Weather & Heliophysics
Intense but Harmless: Exo-Space Weather Around an M Dwarf with a Single-Hemisphere Dynamo
[astro-ph.SR] M dwarfs are among the most promising host stars in the search for habitable exoplanets. However, their active atmospheres drive intense magnetic activity, including energetic flares and possibly coronal […]