Extinction events Archives

Wearing protective gear against toxic gases, Solange Duhamel stands next to a lava flow during an outing to collect samples of freshly deposited lava rock. Credit Christopher Hamilton

Analog Studies, Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Exploration Gear & Tech, Extinction events, Extremeophiles and Extreme Environments, Genomics, Proteomics, Bioinformatics, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Mapping, Geodesy, Cartography, Bathymetry, Mars, Microbiology & Virology, Origin & Evolution of Life, Press Release, Sample Return

Life On Lava: How Microbes Colonize New Habitats

by Keith CowingDecember 19, 2025December 19, 2025

Life has a way of bouncing back, even after catastrophic events like forest fires or volcanic eruptions. While nature’s resilience to natural disasters has long been recognized, not much is […]

A looming planetary impact -- Astrobiology.com

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Extinction events, Habitable Zones, Impact events, Status Report

Planetary Impacts: Friend Or Foe?

by Keith CowingDecember 17, 2025December 17, 2025

Planetary impact events have profoundly influenced the origin of life and the habitability of Earth in both constructive and destructive ways.

Locations of the five stars (yellow circles) that dominate the ionization of the local clouds, shown in Galactic coordinates

Astrochemistry, Astronomy & Telescopes, Extinction events, Habitable Zones, Press Release, Stellar Cartography

Close Brush With Two Hot Stars Left A Mark Just Beyond Our Solar System

by Keith CowingDecember 2, 2025December 2, 2025

Nearly 4.5 million years ago, two large, hot stars brushed tantalizingly close to Earth’s sun. They left behind a trace in the clouds of gas and dust that swirl just […]

Panel (a)-(c) is the snapshots of the REBOUND simulation. Colors represent the angular momentum value of each comet. Those with blue colors have a possibility of entering the inner solar system. The pentagram symbol denotes the Sun, the gray trajectory represents the flyby path of HD7977, and the purple trace illustrates the orbit of the selected comet. The insets inside each plot show the magnified orbit evolutionary of a selected representative comet. Panel (d) is the distribution of angular momentum change of Inner Oort cloud comets. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Extinction events, Interstellar, Status Report

On The Coincidence Between The Close Passage Of HD7977 And The Pliocene-Pleistocene Transition

by Keith CowingNovember 24, 2025November 24, 2025

The Oort Cloud’s dynamical evolution is significantly influenced by both the galactic tide and stellar flybys.

Schematic of episodic atmospheric collapse and regeneration through impacts for a tidally locked planet. A) The planet has a volatile rich atmosphere which redistributes heat from the day- to the nightside. B) Atmospheric escape thins the atmosphere, heat redistribution becomes less efficient, nightside temperatures drop. C) Nightside temperatures have reached the volatile condensation temperature, the atmosphere collapses. D) Volatiles outgassed through volcanism or magma ocean pockets accumulate on the nightside as ice. E) An impactor hits the nightside and vaporises ice and rock. Hot vapour, ejecta, and silicate rain further vaporise the nightside ice sheets (see Section 2.2 for details). An atmosphere is regenerated. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Extinction events, Impact events, Status Report

Atmospheric Collapse And re-inflation Through Impacts For Terrestrial Planets Around M Dwarfs

by Keith CowingOctober 31, 2025October 31, 2025

Detection of an atmosphere around a terrestrial exoplanet will be a major milestone in the field, but our observational capacities are biased towards to tidally locked, close-in planets orbiting M-dwarf […]

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Extinction events, Fossils & Paleontology, Imaging & Spectroscopy, Nomenclature, Systematics, Natural History, Origin & Evolution of Life, Press Release, Water/Hycean Worlds & Oceanography

Neutron Scanning Of Coral Fossils Reveals Earth’s Hidden Climate History

by Keith CowingOctober 8, 2025October 8, 2025

A University of Sydney student has developed a completely new way to peer inside coral fossils to recover lost records of past climate change.

Fraction of atmosphere retained 1 Gyr after a hypothetical Moonforming impact with 𝑓esc = 0.01 and 𝐷max = 100 km, as a function of the initial atmospheric mass (𝑚atm0). Filled circles represent an Earth-like, volatile-rich atmosphere with 𝜇 = 29, and the filled diamonds represent an atmosphere with a primordial (solar) composition with 𝜇 = 2.35. For completely depleted atmospheres (𝑚atm/𝑚atm0 < 10−4 ), the time of depletion (𝑡atm, lost) is indicated by the fill colors. Dotted lines connecting markers of the same 𝜇 values are included as visual guides. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Impact events, Status Report

Re-accretion of Giant Impact Ejecta Can Drive Significant Atmospheric Erosion on Terrestrial Planets

by Keith CowingOctober 8, 2025October 8, 2025

Giant impacts, the collisions between planetary embryos, play a crucial role in sculpting the planets and their orbital architectures.

Impact event that killed the dinosaurs -- NSF

Biogeochemical Cycles & Geobiology, Comets and Asteroids, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Impact events, Meteorites & Asteroids, Status Report

The Depletion Of The Asteroid Belt And The Impact History Of The Earth

by Keith CowingSeptember 29, 2025September 28, 2025

We have evaluated the rate at which the asteroid belt is losing material, and how it splits between macroscopic bodies and meteoritic dust.

(A) Field photograph of exceptional shatter cones near the center of the structure. Photo credit: A.R.B./Harvard University. (B) Geologic map of the structure, which occupies the north flank of North Pole Dome. Red points indicate shatter cone outcrops, which occur within an ~6.47-km–diameter area (blue solid circle) centered on the inferred point of impact (blue square). An inferred total diameter of ~16.2 km for the structure (blue dashed circle) is calculated from scaling laws using the shatter cone occurrence diameter (37). The map data are modified from the GSWA (83) based on our mapping. (C) Context map showing the location within Australia and the Pilbara Craton. -- Science Advances via PubMed

Analog Studies, Astrogeology, Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Extinction events, Impact events, Mapping, Geodesy, Cartography, Bathymetry, Mars, Press Release

Geology And Mars Analog Potential Of The < 2.7-billion-year-old Miralga Impact Structure, North Pole Dome, Pilbara Craton, Australia

by Keith CowingAugust 18, 2025August 18, 2025

North Pole Dome (Pilbara Craton, Western Australia) contains unique geological analogs to early Earth and Mars.

A mollweide map of Earth 275 million years ago, overlayed by a black outline of present-day countries in their respective locations. -- Wikipedia

Biosignatures & Paleobiology, Extinction events, Fossils & Paleontology, Impact events, Press Release

Fossils Shed Light On The Era Before Earth’s Largest Mass Extinction

by Keith CowingAugust 18, 2025August 18, 2025

An international team of paleontologists has spent more than 15 years excavating and studying fossils from Africa to expand our understanding of the Permian, a period of Earth’s history that […]

Extinction events

Life On Lava: How Microbes Colonize New Habitats

Planetary Impacts: Friend Or Foe?

Close Brush With Two Hot Stars Left A Mark Just Beyond Our Solar System

On The Coincidence Between The Close Passage Of HD7977 And The Pliocene-Pleistocene Transition

Atmospheric Collapse And re-inflation Through Impacts For Terrestrial Planets Around M Dwarfs

Neutron Scanning Of Coral Fossils Reveals Earth’s Hidden Climate History

Re-accretion of Giant Impact Ejecta Can Drive Significant Atmospheric Erosion on Terrestrial Planets

The Depletion Of The Asteroid Belt And The Impact History Of The Earth

Geology And Mars Analog Potential Of The < 2.7-billion-year-old Miralga Impact Structure, North Pole Dome, Pilbara Craton, Australia

Fossils Shed Light On The Era Before Earth’s Largest Mass Extinction

PJ Harvey Announces New Song “Voyager”

Fifty Years after Viking: The Promise of Solar System Microbiology and Microbial Ecology

Characterising Transiting Exoplanets At Long Orbital Period: Lessons Learned For PLATO From 10 Years Of Monitoring The HIP41378 System

Implications Of Self-consistent H2O Ice Optical Constants On Radiative Transfer Models Of Disks

The GAPS Programme at TNG LXXIV. A Reanalysis Of The Planetary Systems TOI-1272 And TOI-1694 With HARPS-N And Retraction Of The Planetary Interpretation Of TOI-1272 c