astro-ph.EP Archives

Overview and performance of the LUMOS framework for biogenicity assessment. a, The LUMOS (Life Unveiled using Molecular Orbital Signatures) framework integrates amino acid abundance measurements with quantum chemical descriptors to evaluate biogenicity. First, the abundance of a set of amino acids is estimated, followed by the computation of molecular descriptors (e.g., HOMO–LUMO gap). These descriptors are then weighted by abundance using statistical features such as weighted variance. The resulting value is used to assess the confidence in biogenicity, informed by additional contextual data and environmental provenance. b, Heatmap of P(B|E), the confidence that a sample is biotic (B) given the observed weighted variance (evidence E) as a function of the number of amino acids measured. The prior P(B) is taken as 0.01. Color intensity reflects the biogenicity probability as determined by Bayesian inference applied to simulated distributions of biotic and abiotic samples. c, Criteria met by the LUMOS framework for distinguishing biotic from abiotic amino acid systems. -- astro-ph.EP

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Status Report

Distinguishing Life From Non-life Via Molecular Frontier Orbital Energy Gaps

by Keith CowingFebruary 25, 2026February 26, 2026

Amino acids (AAs) are a key target in the search for life beyond Earth due to their extensive role in the machinery of all known life, persistence over geologic timescales, […]

Subsurface ice final depth interpolated map for latitudes 40-55 North, assuming ice was emplaced 630 kyr ago for 1% dust fraction scenario and no lag layer porosity. The red line represents MONS 7.5% Water-Equivalent Hydrogen contour. The white circles and crosses are locations where ice-exposing craters and maybe ice-exposing craters are found, respectively. The black circles are locations where non-ice-exposing craters are found. The numbers next to the circles indicate the assumed crater depths. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Desert Worlds, Habitable Zones, Icy Worlds, Mars, Status Report

The Martian Mid-latitude Subsurface Ice Is The Remnant Of A Past Ice Sheet

by Keith CowingFebruary 25, 2026February 25, 2026

On Mars, a relatively pure water ice layer lies beneath several centimeters of dry soil at mid-latitudes. Its widespread presence poleward of 60° latitude was detected by remote neutron spectroscopy […]

Illustration of liposome protection from UV. The top panel shows a drawing of the crater. The top- and sideview photographs show the intensity distribution of the blue color after UV exposure. When subjected to UV radiation, the liposomes go through a color change from the original white to blue, with the color intensity correlated with the level of physical destruction of the liposomes. Furthermore, the liposomes change to red when exposed to high heat. The experiment shows that liposomes located at the edges and not covered by the solution turn to blue and then to red within the first few seconds of UV exposure, likely due to the combined effects of UV and heat emitted from the lamp. Liposomes covered by the solution demonstrate a gradual change of the blue color from deep-blue for those at the edge to less intense and almost transparent, deeper toward the center. Even after more than two hours of UV exposure, the liposomes in the crater’s center stayed intact. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Genomics, Proteomics, Bioinformatics, Habitable Zones, Impact events, Origin & Evolution of Life, Panspermia, Sample Return, Status Report

Experimental And Numerical Modeling Of Liposome Congregation In Meteorite Craters Of Early Earth

by Keith CowingFebruary 25, 2026February 25, 2026

This paper provides experimental and numerical evidence supporting the occurrence of liposome congregation at the floors of meteor craters on Early Earth.

Orbital eccentricity (in e2) versus semi-major axis for the planet sample with eccentricities constrained to better than 40% for clarity (or if e < 0.1). Colors denote sub-Neptunes (1–4 R⊕, blue), sub-Saturns (4–8 R⊕, purple), and Jovians (8–16 R⊕, orange). Overlaid curves show theoretical formation channels from R. I. Dawson & J. A. Johnson (2018) for a fiducial planet of ∼6 R⊕ and ∼80 M⊕: high-eccentricity migration (red shaded region) and planet-planet scattering (gray dashed line, gray shaded region). The concentration of larger planets at high eccentricities and small semi-major axes is consistent with high-eccentricity migration. -- astro-ph.EP

Exoplanets, -moons, -comets, Status Report, Stellar Cartography

The Orbital Eccentricity–Radius Distribution for Warm, Single Planets in TESS

by Keith CowingFebruary 25, 2026February 25, 2026

We characterize the radius-dependent eccentricity distribution of 347 warm (P = 8-200 days) systems with only one transiting planetary candidate identified during Sectors 1-69 of the TESS mission.

Completeness and planet abundance plot for the DMPP radial velocity survey of 24 targets with sub-basal activity

Astronomy & Telescopes, Exoplanets, -moons, -comets, Status Report

The Dispersed Matter Planet Project Sample — Detection limits, Occurrence Rates and New Planets

by Keith CowingFebruary 23, 2026February 23, 2026

DMPP is a radial-velocity survey that aims to detect planets around stars exhibiting anomalous activity signatures, consistent with the presence of close-in evaporating planets.

Namib Sand Sea, Ground Penetrating Radar, Yardang, Lut desert,

Analog Studies, Arctic / Antarctic / Alpine, Away Teams & Field Reports, Caves, Craters, Mountains, Subsurface, Lava Tubes, Desert Worlds, Exploration Gear & Tech, Icy Worlds, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Planetary Protection & Biosafety, Polar / Alpine Expeditions, Robotics/Rovers/UAVs, Sample Return, Status Report, Titan, Tricorders & Sensors, Water/Hycean Worlds & Oceanography

Terrestrial Analogs To Titan For Geophysical Research

by Keith CowingFebruary 20, 2026February 20, 2026

Saturn’s moon Titan exhibits remarkable parallels to the Earth in many geophysical and geological processes not found elsewhere in the solar system at the present day.

A 15x15 Full Frame Image cutout centered on the target star TIC 92223525 (green star). The red dots represent the neighboring stars in the Gaia DR3 catalog with Tmag

Astronomy & Telescopes, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

Searching For Extragalactic Exoplanets: A Survey Of The Sagittarius Dwarf Galaxy Stream With TESS

by Keith CowingFebruary 20, 2026February 20, 2026

To date no exoplanets have been detected outside the Milky Way, and their extragalactic occurrence rates are poorly constrained. Using available data from TESS we perform the first transit survey […]

A schematic diagram of the circumstellar gas torus, that has formed due to the accumulation of escaping gas from the planet over many orbits. The left and right panel shows the system geometry when observed top-down (left) and side on (right). -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Observational Signatures Of Circumstellar Gas Tori Formed by Planetary Mass-Loss from Close-In Exoplanets

by Keith CowingFebruary 20, 2026February 20, 2026

Close-in exoplanets with H/He atmospheres often undergo hydrodynamic escape. In extreme cases, it is hypothesized that the mass loss can be high enough for the escaping planetary material to wrap […]

Two-dimensional temperature map of the disk after 280 kyr of evolution. The averaged trajectories of particles over this period, plotted along the 𝑟 and 𝑧 axes, are shown in white. The panels present the trajectories of particles with sizes of 1 cm and 1 𝜇m, released at initial disk temperatures of 20 K (panels a and b) and 80 K (panels c and d). Green triangles indicate the initial positions of the particles, while green crosses mark their final positions. In each panel, the detailed trajectory of an individual particle is highlighted within the square on the right. -- astro-ph.EP

Astrochemistry, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Callisto, Europa, Ganymede, Icy Worlds, Imaging & Spectroscopy, Io, Jupiter, Status Report

Delivery Of Complex Organic Molecules To The System Of Jupiter

by Keith CowingFebruary 20, 2026February 20, 2026

Complex organic molecules are key markers of molecular diversity, and their formation conditions in protoplanetary disks remain an active area of research. These molecules have been detected on a variety […]

Temperature profiles of the CPD at t = 50, 100, 150, and 200 kyr of its evolution. The formation of COMs by thermal processing occurs in the temperature range from 80 K (blue dashed line) to 260 K (red dashed line). At 150 kyr of evolution, a cold region appears in the model, with temperatures too low to support COM formation by thermal processing. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Callisto, Cryobiology, Europa, Ganymede, Habitable Zones, Ice Giant, Io, Jupiter, Missions & Hardware, Status Report

Formation and Survival of Complex Organic Molecules in the Jovian Circumplanetary Disk

by Keith CowingFebruary 19, 2026February 19, 2026

Europa, Ganymede, and Callisto are key targets in the search for habitability due to the potential presence of subsurface oceans. Detecting complex organic molecules (COMs), essential for prebiotic chemistry, is […]

astro-ph.EP

Distinguishing Life From Non-life Via Molecular Frontier Orbital Energy Gaps

The Martian Mid-latitude Subsurface Ice Is The Remnant Of A Past Ice Sheet

Experimental And Numerical Modeling Of Liposome Congregation In Meteorite Craters Of Early Earth

The Orbital Eccentricity–Radius Distribution for Warm, Single Planets in TESS

The Dispersed Matter Planet Project Sample — Detection limits, Occurrence Rates and New Planets

Terrestrial Analogs To Titan For Geophysical Research

Searching For Extragalactic Exoplanets: A Survey Of The Sagittarius Dwarf Galaxy Stream With TESS

Observational Signatures Of Circumstellar Gas Tori Formed by Planetary Mass-Loss from Close-In Exoplanets

Delivery Of Complex Organic Molecules To The System Of Jupiter

Formation and Survival of Complex Organic Molecules in the Jovian Circumplanetary Disk

Relevance of the Avalon Assemblage as an Astrobiological Analog for Icy Ocean Worlds

The Climate and Potential Habitability of a Warm and Oxygenated Mars

Variable X-ray flux May Explain Variable Helium Escape From The Habitable-zone Exoplanet LHS 1140b

Spacetime Contactability in Galactic Civilization Networks: Contact Counts and Percolation

Surprisingly Enriched CO and CH4 in Halley-type Comet 13P/Olbers: Clues to Its Interstellar Heritage