reactive oxygen species Archives

Terrestrial planet with thin atmosphere -- NASA

Biophysics, Enceladus, Europa, Habitable Zones, Mars, Microbiology & Virology, Press Release, Radiation

Estimating The Potential Of Ionizing Radiation-induced Radiolysis For Microbial Metabolism On Terrestrial Planets And Satellites With Rarefied Atmospheres

by Keith CowingJuly 29, 2025July 29, 2025

Ionizing radiation is known to have a destructive effect on biology by causing damage to the DNA, cells, and production of Reactive Oxygen Species (ROS), among other things.

Two proposed mechanisms for H2O2 generation at quartz–water interfaces. (A) Stress-induced cleavage of Si–O bonds. Applied force is represented by a linear falling potential (dashed line), which is added to the Morse potential of the unstretched Si–O bond (dotted line), thus resulting in a force-deformed Morse potential (solid line). The new dissociation energy D′ is smaller than D in the case of a stretching force. Modified after Kauzmann et al. (42). The probability of generation of surface-bound radicals in quartz therefore increases during mechanical processes. (B) Contact of water on freshly fractured surface of abraded quartz. Modified after Schoonen et al. (32). (C) Generation of H2O2 and O2 in the reaction between H2O and oxygen radical (≡SiO•). (D) Generation of rocky H2O2 and O2 in the reaction between H2O and peroxy radical (≡SiOO•). Surface-bound radicals are formed through homolysis of Si–O bonds, including ≡SiO•, ≡SiOO•, and E′ center (≡Si•), while surface charges (≡Si+ and ≡SiO–) for heterolysis. Silanol groups (≡SiOH) are end products on quartz surface after hydroxylation. -- Guangzhou Institute

Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Origin & Evolution of Life, Press Release

A Novel Origin Of Abiotic Oxidants On Early Earth: Minerals

by Keith CowingMarch 23, 2023March 23, 2023

Molecular oxygen (O2) is essential for respiration on today’s Earth, but the early atmosphere was almost devoid of oxygen until the Great Oxidation Event. How then did Earth’s atmosphere become […]

reactive oxygen species

Estimating The Potential Of Ionizing Radiation-induced Radiolysis For Microbial Metabolism On Terrestrial Planets And Satellites With Rarefied Atmospheres

A Novel Origin Of Abiotic Oxidants On Early Earth: Minerals

Training For Astrobiology Spelunking On Mars

Mars Perseverance Rover’s Panoramic View of Broom Point

Planets Orbiting Barnard’s Star Seem To Be Small, Strange, And Utterly Uninhabitable

Experimental Astrochemistry And Machine Learning Unravel The Formation Of Oxygen-bearing Organic Molecules In Extraterrestrial Ices

Bacteria Form Herds To Survive Predators, Offering Fresh Insight Into Earth’s Carbon Cycle