[Astrobiology via PubMed]. Photochemical organic hazes such as those found in the atmosphere of Titan, the largest satellite of Saturn, are mainly composed of reduced chemical components.
Biogeochemical Cycles & Geobiology
Posted inBiogeochemical Cycles & Geobiology
A Geochemical Precursor of ATP
[Heinrich-Heine University Duesseldorf] Where did the energy come from to power the chemical origin of life and how did phosphate come to be the universal energy currency of cells?
Posted inBiogeochemical Cycles & Geobiology
Activity And Diversity Of Sulfate- and Methane-based Pathways Of Anaerobic Chitin And N-acetylglucosamine Degradation In Marine Sediments
[American Society of Microbiology] Sulfate reduction is estimated to account for half of the organic carbon respiration in anoxic, organic-rich ocean sediments. Sulfate-reducing microorganisms (SRMs) typically oxidize simple carbon compounds, […]
Posted inMars
Curiosity Rover Catches A Stunning Martian Dawn
[NASA] A newly released panorama captured by NASA’s Curiosity rover offers the most detailed view yet of distant, wind-carved Martian cliffs, highlighting features the mission’s scientists have long been waiting […]
![Color maps showing statistical uncertainties on the line-of-sight CH3CN Doppler shifts, for four epochs (2016-08-19 to 2022-08-01). Titan’s wireframe grid is shown for each epoch, with the spatial resolution (elliptical beam FWHM) indicated lower left.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Temporal-Variability.png?resize=1200%2C735&ssl=1)
Posted inTitan
Temporal Variability of Titan’s Middle-Atmospheric Zonal Winds from Southern Fall to Late Winter (2016-2023)
[astro-ph.EP] Previous ALMA observations have revealed unexpectedly strong and rapid variations in Titan’s high-altitude equatorial zonal winds, which present a challenge to our understanding of this moon’s atmospheric dynamics.
Posted inExoplanets, -moons, -comets
Hybrid Worlds Are The Commonest Outcome Among The M-dwarf Sub-Neptunes Characterised With JWST
[astro-ph.EP] The sub-Neptunes orbiting M dwarfs are usually assigned to one of two classes: rocky cores beneath primordial hydrogen, or volatile-rich bodies formed beyond the water-ice line.
![Simulated climates and observables for CO2-rich planets near the outer edge of the habitable zone. The illustration on the right depicts a potentially habitable world orbiting a Sun-like star. The teal point in the lower left section of the panel marks the orbital location of such a planet within the OHZ, and the corresponding reflected light spectrum that could be observed via direct imaging is shown in teal in the middle, left section of the panel. The upper left section of the panel shows an illustration of the same planet in a globally frozen state located just beyond the habitable zone. Its orbital position (lower left) and reflected light spectrum (middle) are shown in white. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/High-CO2.png?resize=1200%2C721&ssl=1)
Posted inHabitable Zones
High-CO2 Climates And Observables In The Outer Habitable Zone
[astro-ph.EP] The habitable zone (HZ) is a fundamental concept used to guide our search for temperate exoplanets with stable surface liquid water that would sustain remotely detectable biosignatures.
![Transmission spectra of TRAPPIST-1 c from the four JWST/NIRSpec PRISM epochs (4-pixel bins, 0.8–5.0 𝜇m), offset vertically by 200 ppm per epoch for clarity and colour-coded by date, with the inverse-variance-weighted mean spectrum (black, plotted at its true depth). Grey bands mark the stellar H2O features near 1.4 and 1.85 𝜇m. The dotted line marks 2.0 𝜇m, the boundary of the region where the contamination is strongest (Section 3). The 2023 November 8 visit contains a flare during transit and the 2024 July 9 visit shows activity outside transit (Section 2.5). -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/10/Detecting.png?resize=1200%2C716&ssl=1)
Posted inAstronomy & Telescopes
Detecting Atmospheres In The Presence Of Stellar Contamination: An Empirically Calibrated Framework Applied To Four JWST/NIRSpec PRISM Transits Of TRAPPIST-1c
[astro-ph.EP] Transmission spectroscopy of rocky exoplanets orbiting late M dwarfs is limited by stellar contamination rather than photon noise.
Posted inMars
Sulfate Deposits On Iani Chaos On Mars
[NASA/JPL-Caltech/UArizona] This HiRISE image shows light-toned layered deposits within Iani Chaos. Many of the same deposits occur within the depressions of Iani Chaos, as well as several nearby similar regions […]
Posted inAtmospheres, Climate, Weather
Ancient Seas Reveal Times When The Earth Rapidly Shifted Relative To Its Axis
[AAAS] Ancient sea-level changes provide new evidence that during the Jurassic and Cretaceous, Earth underwent episodes of rapid “true polar wander” (TPW).