Photochemistry Archives

The Expose-R2 facility on the International Space Station. As part of ESA’s Expose-R2 project, 46 species of bacteria, fungi and arthropods are inside those containers as they spend 18 months bolted to the outside of the International Space Station. The vacuum of space is sucking out the water, oxygen and other gases in the samples. Their temperature can drop to –12°C as the Station passes through Earth’s shadow, rising to 40°C at other times, and undergoing a similar process to the freeze-drying used to preserve foods. The Expose experiments are exploring the limits of terrestrial life, whether the organisms can survive in space and how the full blast of solar radiation is affecting accompanying chemicals. -- ESA (larger image)

Analog Studies, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Cryobiology, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Icy Worlds, Microbiology & Virology, Microgravity, Missions & Hardware, Panspermia, Planetary Protection & Biosafety, Space Stations, Status Report, Tricorders & Sensors

ISS Astrobiology Research: Photochemical Evolution of Alanine in Association with the Martian Soil Analog Montmorillonite

by Keith CowingMarch 30, 2025March 30, 2025

The Photochemistry on the Space Station (PSS) experiment was part of the European Space Agency’s EXPOSE-R2 mission and was conducted on the International Space Station from 2014 to 2016. The […]

In black: enzymes and metabolic pathways inferred to be present in LUCA with at least PP = 0.75, with sampling in both prokaryotic domains. In grey: those inferred in our least-stringent threshold of PP = 0.50. The analysis supports the presence of a complete WLP and an almost complete TCA cycle across multiple confidence thresholds. Metabolic maps derived from KEGG47 database through iPath109. GPI, glycosylphosphatidylinositol; DDT, 1,1,1-trichloro-2,2-bis(p-chlorophenyl) ethane. -- Nature

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Origin & Evolution of Life, Status Report

The Nature Of LUCA – The Last Universal Common Ancestor – and its Impact on the Early Earth System

by Keith CowingJanuary 21, 2025January 21, 2025

The nature of the last universal common ancestor (LUCA), its age and its impact on the Earth system have been the subject of vigorous debate across diverse disciplines, often based […]

Graphical Abstract -- Acc Chem Res via PubMed

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

Chemical Kinetics As A Window Into Prebiotic Plausibility

by Keith CowingJanuary 21, 2025January 21, 2025

Origin of Life research is a fast growing field of study with each year bringing new breakthroughs. Recent discoveries include novel syntheses of life’s building blocks, mechanisms of activation and […]

Validation and low-cost schemes’ performance on key and major molecules. The plots illustrate the performance of our method on key molecules for HD 209458b (a) and HD 189733b (b). Left: Molar fractions of key molecules as a function of pressure in the atmosphere. The full V20 model is represented by a solid line, DARWEN’s validation scheme by a dashed-dotted line, low-cost schemes by a dashed line, and the reduced scheme (R20) by a dotted line. Right: Maximal percentage changes in the molar fractions of the key molecules compared to the full model. The full model’s line is not shown because it serves as the reference model. Lines close to zero indicate that the predictions are nearly identical to those of the full model for that molecule. We only show changes bigger than 1%. -- astro-ph.EP

AI - Data - Apps - Cybernetics, Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Status Report

DARWEN: Data-driven Algorithm for Reduction of Wide Exoplanetary Networks

by Keith CowingDecember 11, 2024December 11, 2024

Exoplanet atmospheric modeling is advancing from chemically diverse one-dimensional (1D) models to three-dimensional (3D) global circulation models (GCMs), which are crucial for interpreting observations from facilities like the James Webb […]

Although flare rates and energies are measured in the optical for most stars, the FUV and NUV energies determine the photochemical radiation environment of orbiting planets during these events. Simultaneous observations at UV and optical wavelengths are needed to derive the energy budget as flares with similar emission levels at optical wavelengths can produce NUV fluxes that differ by 2–20× depending on the Teff of the flare, correlating with order-of-magnitude discrepancies at FUV wavelengths. Spectra of ϵ Eri during the two flares are obtained by superimposing the flare blackbody onto the semi-empirical base spectrum from Behr et al. (2023). -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Missions & Hardware, Radiation, Space Weather & Heliophysics, Status Report, Stellar Cartography

Preparing For The Early eVolution Explorer

by Keith CowingNovember 18, 2024November 18, 2024

Ultraviolet flare emission can drive photochemistry in exoplanet atmospheres and even serve as the primary source of uncertainty in atmospheric retrievals. Additionally, flare energy budgets are not well-understood due to […]

A habitable world -- Grok via Astrobiology.com

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Origin & Evolution of Life, Status Report

Building and Maintaining a Habitable World and the Early Conditions that Could Favor Life’s Beginnings on Earth and Beyond

by Keith CowingNovember 1, 2024

The Hadean, once thought to be uninhabitable and tumultuous, has more recently been recontextualized as a clement time in which oceans, land, and life likely appeared on Earth. This non-exhaustive […]

UV absorption cross sections for the phosphorus species in the network that undergo photolysis reactions. The photolysis threshold wavelength for each species is indicated by the coloured arrows. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Jupiter, Saturn, Status Report, Water/Hycean Worlds & Oceanography

A Photochemical PHO Network For Hydrogen-dominated Exoplanet Atmospheres

by Keith CowingSeptember 13, 2024September 13, 2024

Due to the detection of phosphine PH3 in the Solar System gas giants Jupiter and Saturn, PH3 has long been suggested to be detectable in exosolar substellar atmospheres too. However, […]

An international team of researchers led by the University of Bern has used observation-based computer modelling to find an explanation for how macromolecules can form in a short time in disks of gas and dust around young stars. These findings could be crucial for understanding how habitability develops around different types of exoplanets and stars.

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Interstellar, Meteorites & Asteroids, Press Release

Astronomers Clarify How Organic Macromolecules Are Formed

by Keith CowingJuly 31, 2024July 31, 2024

An international team of researchers led by the University of Bern has used observation-based computer modelling to find an explanation for how macromolecules can form in a short time in […]

Contribution functions at selected wavenumbers calculated for the best-fitting models (Fig. 5) of CIRS (red lines) and TEXES (blue lines) observations. These contribution functions, which have been normalized at each wavenumber, are Jacobians that give the rate of change of spectral flux with temperature (Panel A), logarithm of C2H2 mole fraction (Panel B), and logarithm of C2HD mole fraction (Panel C). -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report, Titan

The D/H Ratio in Titan’s Acetylene From High Spectral Resolution IRTF/TEXES Observations

by Keith CowingJuly 31, 2024July 31, 2024

We report observations of deuterated acetylene (C2HD) at 19.3 μm (519 cm−1) with the Texas Echelon Cross Echelle Spectrograph on the NASA Infrared Telescope Facility in July 2017.

The detections of H2O, CO, and total atmospheric signal in the atmosphere of WASP-127 b. The CC maps shown here are generated by cross-correlating the residual data with solar composition RCTE models with opacity from H2O alone, CO alone, and all absorbers respectively. The tellurics have been masked and the out-of-transit frames have been cropped in the residual data. The white dashed lines in these maps denote the literature reported values of Vsys0 and Kp0 for the WASP-127 b system. The red cross indicates the peak value of the SNR within each map. Similar to the trail, the peak signal in these maps can be seen blue shifted. The bottom red curves under each panel shows the row/cross-section of the CC SNRs at the peak Kp. -- astro-ph.EP

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

IGRINS Observations of WASP-127 b: H2O, CO, and Super-Solar Atmospheric Metallicity in the Inflated sub-Saturn

by Keith CowingJune 21, 2024June 21, 2024

High resolution spectroscopy of exoplanet atmospheres provides insights into their composition and dynamics from the resolved line shape and depth of thousands of spectral lines. WASP-127 b is an extremely […]