Atmospheres, Climate, Weather Archives

β Pic d possible orbits and stability fractions. Left: Allowed orbits (pink) from Octofitter (W. Thompson et al. 2023) posteriors fit to astrometry and planetary RV (black) reported in Table 1, projected on-sky. Possible orbits are also shown in RV space. The locations of β Pic b and the approximate inner edge of the debris disk are plotted for reference. β Pic c is not shown as it falls nearly coincident with the star. Right: Fraction of stable orbits as a function of β Pic d mass and semi-major axis, as determined by the MEGNO chaos indicator from orbit posteriors integrated over 5 Myr. The semi-major axis range of the 68% percentile orbit posteriors is overlaid in pink. Orbital period ratios with β Pic b are shown as white dashed lines. The pink shaded region represents the 68th percentile of the orbital posteriors. The current astrometric baseline and RV precision do not strongly constrain the orbit; however, stability requirements suggest a semi-major axis of > 30 au. -- astro-ph.EP

Discovery Of An Exterior Third Planet Orbiting β Pictoris

by Keith CowingJuly 2, 2026July 2, 2026

[astro-ph.EP] We report the discovery of β Pictoris d (β Pic d), a third giant planet in the β Pictoris system, which now becomes only the second directly imaged system […]

Transmission spectra of TOI-6894 b from two independent reductions

Exoplanets, -moons, -comets

C,N,O,S, And Photochemistry In A Temperate Giant Planet Orbiting A Late M Dwarf

by Keith CowingJuly 2, 2026July 2, 2026

[astro-ph.EP] We report the JWST NIRSpec/PRISM transit spectrum of TOI-6894b, an exceptional 420 K sub-Saturn that is the only known giant planet transiting a late M dwarf. Remarkably, both the […]

ID: ESP_077054_1825 date: 3 January 2023 altitude: 271 km NASA/JPL-Caltech/University of Arizona larger image

Mars

Sulfates Or Other Hydrated Materials East Of Aram Chaos?

by Keith CowingJuly 2, 2026July 2, 2026

[NASA] Aram Chaos is of particular scientific interest because it is hypothesized that its chaotic terrain may be the source of water that contributed to the creation of nearby valleys […]

Location: Baltic Sea Credit: European Union, Copernicus Sentinel-3 imagery Larger image -- European Union

Biosignatures & Paleobiology

Orbital Biosignature Assay: Summer Algal Bloom Spreads Across The Baltic Sea

by Keith CowingJuly 1, 2026July 1, 2026

[European Union] During the summer months, large algal blooms occur frequently in the Baltic Sea. Often driven by warmer temperatures, abundant sunlight, and nutrient-rich waters, these blooms can reduce water […]

Flowchart summarizing the proposed Nautilus time-resolved flare spectroscopy program.

Habitable Zones

Nautilus: Fast Time-Resolved Spectroscopy of GKM Stellar Flares and Their Implications for Planetary Habitability

by Keith CowingJune 30, 2026June 30, 2026

[astro-ph.SR] Low-mass GKM dwarfs are prime targets for finding habitable-zone Earth-sized planets, but their frequent flares, especially on M~dwarfs, can strongly affect planetary atmospheres through enhanced UV/XUV radiation and stellar […]

Figure summarizing the key science objectives. -- astro-ph.IM

Exoplanets, -moons, -comets

Nautilus Space Observatory: The Evolution of Planets and their Atmospheres

by Keith CowingJune 29, 2026June 29, 2026

[astro-ph.IM] We are just beginning to explore the billion-year evolution from nascent planets in disks to mature planetary systems. Recent discoveries hint at demographic and atmospheric differences between young planets […]

Particle temperature normalized by the gas temperature as a function of pressure and particle radius for SiO2, Mg2SiO4, Fe, and Al2O3. The hatched region denotes the phase space where the particle temperature exceeds the condensation temperature, leading to the sublimation of clouds. -- astro-ph.EP

Exoplanets, -moons, -comets

Radiatively Controlled Thermal Stability of High-Altitude Clouds in Exoplanetary Atmospheres

by Keith CowingJune 27, 2026June 27, 2026

[astro-ph.EP] One of the most striking findings of exoplanetary science is the ubiquity of clouds. A conventional approach to infer the cloud compositions is to utilize the thermochemical equilibrium model […]

A: The average relative photosynthetic output rate, ν/νmax, as a function of main sequence stellar temperature/mass and orbital semi-major axis, a, for oxygenic, anoxygenic and hypothetical forms of photosynthesis (denoted by green crosses, red circles and blue triangles respectively). The error bars represent variance in antenna structure in the final evolved photosynthetic population output by the genetic algorithm. The faint dashed lines are a visual reference showing a 1/a2 dependence. B: The habitable zone (green) overlaid with contours of constant ν/νmax (coloured dashed lines) for oxygenic photosynthesis. The contours are interpolated from the data points which are shown as filled circles and the corresponding values of ν/νmax are shown as a percentage. For reference, several candidates worlds from the Habitable Worlds Catalogue (PHL UPR Arecibo 2026) are listed, alongside Earth. C: Same as B but for anoxygenic photosynthesis. D: Same as B but for the hypothetical NIR-driven oxygenic photosynthesis. Since only three stellar temperatures/masses were considered for the hypothetical form of photosynthesis (due to calculation cost), we added interpolated data points to generate the contours. -- astro-ph.EP

Uncategorized

An Agnostic Machine Learning Model of Photosynthetic Habitability

by Keith CowingJune 26, 2026June 26, 2026

The search for exoplanet biosignatures is guided by whether planetary environments can sustain photosynthesis.

Mars

Turbulence-coupled Electrodynamics Of The Martian Year 34 Global Dust Storm On Mar

by Keith CowingJune 23, 2026June 23, 2026

We studied the electrodynamic environment during the Martian year 34 (MY 34) global dust storm using data from the Mars Climate Database v.6.1. Our physics-based approach looked at triboelectric charging, […]

Illustration of key factors affecting subsurface ocean habitability and possible chemical evolution in icy moons Factors with question marks are still under debate. -- The Innovation via PubMed

Icy Worlds

Dynamic Controls On Subsurface Water Chemistry And Habitability On Icy Moons

by Keith CowingJune 23, 2026June 23, 2026

Icy moons are natural satellites whose surfaces contain a substantial fraction of frozen materials, most notably water ice.

Atmospheres, Climate, Weather

Discovery Of An Exterior Third Planet Orbiting β Pictoris

C,N,O,S, And Photochemistry In A Temperate Giant Planet Orbiting A Late M Dwarf

Sulfates Or Other Hydrated Materials East Of Aram Chaos?

Orbital Biosignature Assay: Summer Algal Bloom Spreads Across The Baltic Sea

Nautilus: Fast Time-Resolved Spectroscopy of GKM Stellar Flares and Their Implications for Planetary Habitability

Nautilus Space Observatory: The Evolution of Planets and their Atmospheres

Radiatively Controlled Thermal Stability of High-Altitude Clouds in Exoplanetary Atmospheres

An Agnostic Machine Learning Model of Photosynthetic Habitability

Turbulence-coupled Electrodynamics Of The Martian Year 34 Global Dust Storm On Mar

Dynamic Controls On Subsurface Water Chemistry And Habitability On Icy Moons

Rethinking The Origin Of Life At Seafloor Hydrothermal Vents

Proto-Biosignatures and Planetary Geochemical Metabolism: A Thermodynamic Screening Model of Prebiotic Geochemical Organization

Cultivation Of Halophilic Archaea In Shallow Subsurface Martian Conditions Has Implications For Extant Life On Mars

Roman Space Telescope Leaves Earth

Atmospheric Retrieval of Combined JWST, HST, and Ground-Based Observations Reveals a Featureless Transmission Spectrum for GJ 1132 b