Earth Archives

Schematic diagrams highlighting the interesting components of emission from a binary neutron star merger at two different temporal and spatial scales. In (a), the system is shown at sub-parsec scales and within the first few years after the merger. The locations of gamma-ray emission in the dynamical ejecta and the cocoon surrounding the jet are highlighted, as well as the X-ray emission from the interaction between the jet and the interstellar medium (ISM). While the jet and cocoon emission are short-lived, the afterglow produces continuum emission for many years. Only the emitted X-rays produce the fluence that could be lethal. The kilonova, i.e., the UV/optical/IR emission powered by radioactivity in the ejecta, is also shown for additional context, but is undetectable after a week. In (b), the larger, late-time structure of the remnant is shown with the long-since dissipated jet location indicated. The explosion from the merger will launch a strong shock that sweeps out a bubble-like structure as it expands through the ISM, which is a source of potentially threatening cosmic rays. -- astro-ph.HE

Astronomy & Telescopes, Extinction events, Radiation, Status Report

Could A Kilonova Kill: A Threat Assessment

by Keith CowingOctober 19, 2023October 19, 2023

Binary neutron star mergers (BNS) produce high-energy emissions from several physically different sources, including a gamma-ray burst (GRB) and its afterglow, a kilonova, and, at late times, a remnant many […]

The deep-blue sea is turning a touch greener.

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Water/Hycean Worlds & Oceanography

Global Biosignatures: Climate Change Lends New Color To Earth’s Ocean

by Keith CowingOctober 14, 2023October 14, 2023

Editor’s note: something to keep in mind as we move towards direct observation of the surfaces and atmospheres of exoplanets. ______

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Earth As An Exoplanet. III. Using Empirical Thermal Emission Spectra as Input for Atmospheric Retrieval of an Earth-Twin Exoplanet

by Keith CowingOctober 7, 2023October 7, 2023

In this study, we treat Earth as an exoplanet and investigate our home planet by means of a potential future mid-infrared (MIR) space mission called the Large Interferometer For Exoplanets […]

Sedimentary rocks on the banks of the Mackenzie River, Canada, a major river basin where rock weathering is a CO2 source. Image credit: Robert Hilton.

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Press Release

Ancient Carbon In Rocks Releases As Much Carbon Dioxide As The World’s Volcanoes

by Keith CowingOctober 5, 2023October 4, 2023

A new study led by the University of Oxford has overturned the view that natural rock weathering acts as a CO2 sink, indicating instead that this can also act as […]

A seismic image of the Hikurangi plateau reveals details about the Earth’s interior and what it’s made of. The blue-green layer under the yellow line shows water buried within rocks. Researchers at the University of Texas Institute for Geophysics think the water could be dampening earthquakes at the nearby Hikurangi subduction zone. CREDIT Andrew Gase

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Press Release, Water/Hycean Worlds & Oceanography

Earth’s Massive Undersea Water Reservoir

by Keith CowingOctober 4, 2023October 4, 2023

Researchers have discovered a sea’s worth of water locked within the sediment and rock of a lost volcanic plateau that’s now deep in the Earth’s crust. Revealed by a 3D […]

Schematic illustration of transport and mixing between different isotopic reservoirs during growth of Mars and Earth. Mars was born near the inner edge of the main asteroid belt, in between the ℰ and � reservoirs. It started accreted an equal mixture of both planetesimals (A) but progressively accreted more ℰ material as it migrated inwards into the ℰ region by type I migration (B). During those times, carbonaceous asteroids from the outer solar system were scattered inwards by the giant planets, but interaction with nebular gas led to their implantation into the outer main belt. Larger carbonaceous objects were less subjected to gas drag and were able to penetrate in the inner solar system. Earth grew later primarily from ℰ -type embryos (C). Several tens of millions of years after solar system formation, one or several interloper carbonaceous embryos implanted in the inner disk during the first phase were stochastically accreted by the Earth (D). -- astro-ph.EP

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Mars, Status Report

Bayesian Inference On The Isotopic Building Blocks Of Mars And Earth

by Keith CowingSeptember 30, 2023September 30, 2023

Isotopic anomalies provide a means of probing the materials responsible for the formation of terrestrial planets. By analyzing new iron isotopic anomaly data from Martian meteorites and drawing insights from […]

Reef sharks cruise along a forereef slope, Palmyra Atoll. CREDIT Brian Zgliczynski

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Press Release, Societal Issues, Terraforming & Geoengineering

Theories About The Natural World May Need To Change To Reflect Human Impact

by Keith CowingSeptember 25, 2023September 25, 2023

New research, reported in Nature Ecology & Evolution, (25 September 2023) has for the first time validated at scale, one of the theories that has underpinned ecology for over half […]

Earth’s observed cloud-free transit transmission spectrum from Macdonald & Cowan (2019) binned to a resolution of ∆λ = 0.02 µm and fit using smarter. The data are shown in black, the best-fitting model (Model 1) spectrum is shown in white and blue, and various colors are used to indicate each molecule’s contribution to the model spectrum. The most prominent features are due to CO2 and O3, but a rich diversity of habitability indicators, biosignatures, and technosignatures are present. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, SETI & Technosignatures, Status Report

Earth As A Transiting Exoplanet: A Validation Of Transmission Spectroscopy And Atmospheric Retrieval Methodologies For Terrestrial Exoplanets

by Keith CowingAugust 29, 2023August 29, 2023

The James Webb Space Telescope (JWST) will enable the search for and characterization of terrestrial exoplanet atmospheres in the habitable zone via transmission spectroscopy.

Phanerozoic biodiversity curves. (a) Total Phanerozoic diversity based on raw data82 divided into its three main Evolutionary Faunas (EF), i.e. the Cambrian trilobites, the Paleozoic brachiopods, and the modern gastropods. Tese are three distinct types of fauna whose diversity pattern expanded and contracted in a similar fashion throughout the diferent phases of the Phanerozoic. Each EF includes specifc taxonomic classes that were most abundant during (but not limited to) a certain period in Earth’s history. Furthermore, the EFs successively replaced one another as the principal group throughout the Phanerozoic. Te red arrows represent the Big Five mass extinction events, including the Ordovician–Silurian extinction (~445 Ma ago), Devonian extinction (~375 Ma ago), Permian–Triassic extinction (~250 Ma ago), Triassic-Jurassic extinction (~200 Ma ago) and the Cretaceous-tertiary extinction (~66 Ma ago)81. (b) Corrected biodiversity curve using the shareholder quorum subsampling (SQS) sample standardization method34. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Status Report

Variations In Climate Habitability Parameters And Their Effect On Earth’s Biosphere During The Phanerozoic Eon

by Keith CowingAugust 16, 2023August 16, 2023

Essential insights on the characterization and quality of a detectable biosphere are gained by analyzing the effects of its environmental parameters. We compiled environmental and biological properties of the Phanerozoic […]

Time histories of the altitude profiles of the collision rate per electron obtained by a series of simulations with mirror force. The initial kinetic energy of (a, d, g) 1 keV, (b, e, h) 3 keV, and (c, f, i) 10 keV and the initial pitch angle of (a–c) 0 degree, (d–f) 30 degree, and (g–i) 60 degree are assumed at 400 km -- Tohoku University

Atmospheres, Climate, Weather, Biophysics, Magnetic Fields, Electromagnetism, bioelectricity,, Press Release, Radiation

Geomagnetic Field Protects Earth From Electron Showers

by Keith CowingAugust 4, 2023August 4, 2023

Understanding the ionosphere high in the Earth’s atmosphere is important due to its effects on communications systems, satellites and crucial chemical features including the ozone layer. New insights into the […]

Earth

Could A Kilonova Kill: A Threat Assessment

Global Biosignatures: Climate Change Lends New Color To Earth’s Ocean

Earth As An Exoplanet. III. Using Empirical Thermal Emission Spectra as Input for Atmospheric Retrieval of an Earth-Twin Exoplanet

Ancient Carbon In Rocks Releases As Much Carbon Dioxide As The World’s Volcanoes

Earth’s Massive Undersea Water Reservoir

Bayesian Inference On The Isotopic Building Blocks Of Mars And Earth

Theories About The Natural World May Need To Change To Reflect Human Impact

Earth As A Transiting Exoplanet: A Validation Of Transmission Spectroscopy And Atmospheric Retrieval Methodologies For Terrestrial Exoplanets

Variations In Climate Habitability Parameters And Their Effect On Earth’s Biosphere During The Phanerozoic Eon

Geomagnetic Field Protects Earth From Electron Showers

ExoPAG 35 – Early Career Talks Invitation

Missed Detections and False Alarms in a CNN Technosignature Detector on Breakthrough Listen Data

Ancient Clays Near The Hellas Basin On Mars

A Hydrogen Atmosphere Could Keep Exomoons Habitable For Billions Of Years

Ring Pattern Reveal The Mechanism By Which Unseen Planets And Dust Particles Gather On Their Own