anthropogenic Archives - Astrobiology

Barrel sampling. ROV recovering a sediment push core. -- PNAS Nexus

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Microbiology & Virology, Nomenclature, Systematics, Natural History, Origin & Evolution of Life, Planetary Protection & Biosafety, Press Release, Robotics/Rovers/UAVs, Sample Return, Water/Hycean Worlds & Oceanography

Extremophile Hotspots Linked To Containerized Industrial Waste Dumping In A Deep-sea Basin

by Keith CowingSeptember 28, 2025September 28, 2025

Editor’s note: Over the past several decades our definition of “life as we know it” on Earth has undergone a paradigm shift as we have discovered various “extremophiles” living in […]

(a) Cross sections of four different PAHs in the UV region (0.2-0.4 µm). On average, Naphthalene, Anthracene, and Pyrene have stronger cross-sections among all 4 considered. (b) Collective cross sections of PAHs and other molecules on Earth (taken from Kopparapu et al. (2021)) for the wavelength coverage of a nominal 8m class Habitable Worlds Observatory (0.2-2 µm). PAHs have stronger features than other molecules in this region. The region between 0.3-0.4 µm serves as a promising window to detect PAHs due to the least overlap with other molecular cross-sections. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, SETI & Technosignatures, Status Report

Polycyclic Aromatic Hydrocarbons (PAHs) As An Extraterrestrial Atmospheric Technosignature

by Keith CowingJanuary 14, 2025January 14, 2025

Polycyclic Aromatic Hydrocarbons are prevalent in the universe and interstellar medium but are primarily attributed to anthropogenic sources on Earth, such as fossil fuel combustion and firewood burning.

Spatial patterns in cGENIE DIC δ13C excursion size and water mass age in response to −1‰ CIE. (A) Relative size of the δ13C excursion recorded for each model grid relative to the mean δ13C excursion in the ocean layer centered at ~3,300 m water depth. δ13C excursions are calculated as the DIC δ13C value at 11 ky less the initial value in that grid. Red colors (more negative) indicate CIEs larger than the average. (B) Atlantic zonal mean size of the δ13C excursion relative to the atmospheric δ13C excursion. δ13C excursions are calculated as the DIC δ13C value at 11 ky less the initial value. Contours show the Atlantic Meridional Overturning streamfunction at 11 ky calculated using the mask in SI Appendix, Fig. S1 (for comparison to the global streamfunction, see SI Appendix, Fig. S2). (C) Relative size of the change in water mass age recorded for each model grid relative to the mean change in water mass age in the ocean layer centered at ~3,300 m water depth. Changes in water mass age are calculated as the water mass age at 11 ky less the initial age in that grid. Red colors indicate larger increases in water mass age than the global average. -- PNAS

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Press Release, Water/Hycean Worlds & Oceanography

Ancient Ocean Slowdown Warns Of Future Climate Chaos On Earth

by Keith CowingJune 13, 2024June 13, 2024

When it comes to the ocean’s response to global warming, we’re not in entirely uncharted waters. A UC Riverside study shows that episodes of extreme heat in Earth’s past caused […]

The surface temperature is displayed for the four PCb simulations used in this work: PCb PI (top left), PCb 10% PAL (top right), PCb 1% PAL (bottom left), PCb 0.1% PAL (bottom right). White arrows indicate the magnitude and direction of the surface winds. The magenta contours show surface temperatures of 273 K. For scale, a 10 m s-1 arrow is shown in the middle of the figure. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Proxima Centauri, Space Weather & Heliophysics, Status Report, TRAPPIST-1

Lethal Surface Ozone Concentrations Are Possible On Habitable Zone Exoplanets

by Keith CowingMay 31, 2024

Ozone (O3) is important for the survival of life on Earth because it shields the surface from ionising ultraviolet (UV) radiation. However, the existence of O3 in Earth’s atmosphere is […]