Gaia - Planetary Perspectives Archives - Page 37 of 40

Impact event - Don Davis (work commissioned by NASA)

Extinction events, Fossils & Paleontology, Gaia - Planetary Perspectives, Genomics, Proteomics, Bioinformatics, Impact events, Plant Biology, Press Release

Flowering Plants Survived The Mass Extinction That Killed The Dinosaurs

by Keith CowingDecember 20, 2023December 20, 2023

A new study by researchers from the University of Bath (UK) and Universidad Nacional Autónoma de México (Mexico) shows that flowering plants escaped relatively unscathed from the mass extinction that […]

Runaway greenhouse effect can transform a temperate habitable planet with surface liquid water ocean into a hot steam dominated planet hostile to any life. © Thibaut Roger / UNIGE

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Impact events, Press Release, Terraforming & Geoengineering, Water/Hycean Worlds & Oceanography

Exoplanet Climate: It Takes Nothing To Switch From Habitable To Hell

by Keith CowingDecember 18, 2023December 18, 2023

The Earth is a wonderful blue and green dot covered with oceans and life, while Venus is a yellowish sterile sphere that is not only inhospitable but also sterile. However, […]

The power spectra of the uniform weighting map shown in the central row of Figure 3. The shaded regions around the evolved Earth spectra represent the 1σ ranges of a set of 100 randomized simulations. The dashed lines highlight that, under the constraints of this model and its assumptions, the transformation of the surface consists of two essentially distinct steps: the smoothing of the continent/ocean bimodality via diffusion (shown by the red dashed lines), and the subsequent build-up of surface features through volcanic outflows (in green). This result implies that, while our model nominally assumes a constant surface diffusion rate and a fixed period of volcanism, the results will be virtually identical for equal values of the total diffusion (parametrized by ∆ in Table 1) and total volcanic outflow mass. -- astro-ph.EP

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

Turning Earth Into Venus: A Stochastic Model of Possible Evolutions of Terrestrial Topography

by Keith CowingDecember 12, 2023December 12, 2023

Venus may have had both an Earth-like climate as well as extensive water oceans and active (or incipient) plate tectonics for an extended interval of its history. The topographical power […]

Number of generic extinctions per century among in different classes of vertebrates. The low number of reptiles and amphibia, which underestimate the magnitude of extinction pattern, is probably the result of the lack of information in earlier centuries, where very few species had been described. The dotted line represent the background extinction rate. PNAS

Extinction events, Gaia - Planetary Perspectives, Press Release

Human-driven Mass Extinction Is Eliminating Entire Branches Of The Tree Of Life

by Keith CowingDecember 11, 2023

The passenger pigeon. The Tasmanian tiger. The Baiji, or Yangtze river dolphin. These rank among the best-known recent victims of what many scientists have declared the sixth mass extinction, as […]

Illustration of the modeling combination between a Genome-Scale Model (GSM), i.e., Prochlorococcus MED4 GSM, and an Earth Systems Model (ESM), i.e., NEMO-PISCES, and comparison between growth rates estimated from ESM and GSM. a |From a metabolic network, we defined a solution space embedding all possible fluxes that go through each network reaction. These fluxes satisfy the quasi-steady states assumption and other thermodynamic constraints defined in the GSM. This set of constraints (C1) is defined as biotic constraints, and they affect inner reactions, as well as exchange reactions responsible for the uptake or secretion of nutrients, and a biomass reaction simulating the growth of the organism (color scale similar to panel d., see Appendix 1 for details). b |Earth Systems Models predict global ocean biogeochemistry across space and time. Here the ESM provides uptake fluxes of nutrients for each grid point for each modeled organism. In our framework, these uptake values are used as a set of constraints (C2) on the exchange reactions of the GSM. These are defined as the set of abiotic constraints that are applied in the model. c |C1 and C2 are combined to constrain further exchanged metabolite fluxes at each grid point of the global ocean. As a result, we can estimate the organismal growth rate and all feasible inner fluxes corresponding to a given environment as proposed by the ESM. d |Description of growth rates (h−1) at 5 m depth estimated from NEMO-PISCES picophytoplankton (top) and Prochlorococcus MED4 GSM (bottom). The dashed line shows the transect described in the following panel. e |Distribution of respective growth rates across latitudes and depths at longitude -24o. Grey areas indicate latitudes that do not allow Prochlorococcus MED4 growth because of thermal limits; the GSM does not consider them. The relationship between growth rates across space (above 500 m) and time (i.e., without gray areas) shows R2:0.80 and slope: 0.787 (see Extended Fig. 11). -- biorxiv.org

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Genomics, Proteomics, Bioinformatics, Microbiology & Virology, Status Report, Water/Hycean Worlds & Oceanography

Modeling Genome-scale Knowledge In Earth’s Global Ocean

by Keith CowingDecember 4, 2023December 3, 2023

Editor’s note: As we make plans to do orbital and surface sorties on other worlds searching for life it is certainly useful to use Earth and its diverse biota as […]

Analog Studies, Away Teams & Field Reports, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Genomics, Proteomics, Bioinformatics, Habitable Zones, Status Report

Planetary Scale Assay Of Earth Life: The Monarch Initiative In 2024: An Analytic Platform Integrating Phenotypes, Genes And Diseases Across Species

by Keith CowingDecember 3, 2023December 2, 2023

Editor’s note: As we make plans to do orbital and surface sorties on other worlds searching for life it is certainly useful to use Earth and its diverse biota as […]

a, goSPL12,13 simulations showing high-resolution palaeo-landscape, heterogeneous landforms and drainage networks, under the influence of surface processes, at 155 Ma and 11 Ma. b, Erosion and sedimentation rates; positive values correspond to deposition in endorheic basins and depressions, and negative ones to erosion across mountain ranges and along major river upstream channels, at 155 Ma and 11 Ma. -- Nature

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Extinction events, Gaia - Planetary Perspectives, Press Release

Planetary Landscape Dynamics Determined The Evolution Of Biodiversity On Earth

by Keith CowingNovember 29, 2023November 29, 2023

Movement of rivers, mountains, oceans and sediment nutrients at the geological timescale are the central drivers of Earth’s biodiversity, new research published today in Nature has revealed.

Artist's rendering of a trilobite based on preserved soft body parts. CREDIT Nobu Tamura

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Gaia - Planetary Perspectives, Mapping, Geodesy, Cartography, Bathymetry, Press Release

Trilobite Fossils Help Draw A Map Of Early Earth

by Keith CowingNovember 26, 2023November 26, 2023

Ten newly discovered species of trilobites, hidden for 490 million years in a little-studied part of Thailand, could be the missing pieces in an intricate puzzle of ancient world geography.

One possible unfolding of the SBS game with N = 25 and M = 6. At t = 1 we have our initial ensemble, at t = 2 we have removed all the 1s, at t = 3 we remove all the 2s etc. -- q-bio.PE

AI - Data - Apps - Cybernetics, Biophysics, Gaia - Planetary Perspectives, Origin & Evolution of Life, Status Report

Does Gaia Play Dice?: Simple Models Of Non-Darwinian Selection

by Keith CowingNovember 23, 2023November 22, 2023

In this paper we introduce some simple models, based on rolling dice, to explore mechanisms proposed to explain planetary habitability.

A summary of planet properties at the onset of XUV photoevaporation from models in Figure 6 with constant equilibrium temperatures of 600K, 900K, 1200K, and 1500K in blue, green, orange and red respectively. We assume the disc disperses at 𝑡disp = 3 × 106 yrs with a disc dispersal timescale of 𝜏disp = 105 yrs, all of which lead to XUV photoevaporation dominating at ∼ 4 Myrs, which coincides with the local protoplanetary disc having completely dispersed in these models. The left-hand panel shows the atmospheric mass fraction. Green lines with squares represent results from Owen & Wu (2016), for which boil-off was performed at 900K with initial atmospheric mass fractions of 0.3 and 0.1 in dot-dashed and dotted lines, respectively (note that initial atmospheric mass fractions in our models are calculated self-consistently through gaseous accretion). The right-hand panel shows planet sizes, including those that have been stripped of their atmosphere (atmospheric mass fraction < 10−4 ) and sit on an Earth-like composition line (grey dashed). This panel can be interpreted as a primordial mass-radius distribution. -- astro-ph.EP

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

Under The Light Of A New Star: Evolution Of Planetary Atmospheres Through Protoplanetary Disc Dispersal And Boil-off

by Keith CowingNovember 22, 2023November 22, 2023

The atmospheres of small, close-in exoplanets are vulnerable to rapid mass-loss during protoplanetary disc dispersal via a process referred to as `boil-off’, in which confining pressure from the local gas […]

Gaia – Planetary Perspectives

Flowering Plants Survived The Mass Extinction That Killed The Dinosaurs

Exoplanet Climate: It Takes Nothing To Switch From Habitable To Hell

Turning Earth Into Venus: A Stochastic Model of Possible Evolutions of Terrestrial Topography

Human-driven Mass Extinction Is Eliminating Entire Branches Of The Tree Of Life

Modeling Genome-scale Knowledge In Earth’s Global Ocean

Planetary Scale Assay Of Earth Life: The Monarch Initiative In 2024: An Analytic Platform Integrating Phenotypes, Genes And Diseases Across Species

Planetary Landscape Dynamics Determined The Evolution Of Biodiversity On Earth

Trilobite Fossils Help Draw A Map Of Early Earth

Does Gaia Play Dice?: Simple Models Of Non-Darwinian Selection

Under The Light Of A New Star: Evolution Of Planetary Atmospheres Through Protoplanetary Disc Dispersal And Boil-off

Compatible Comma-Free Codes and the Origin of the Genetic Code

Simulations Of The Evolving Ozone Layer: Implications For The Early Earth, Exoplanets, And The Search For Life

VUV And mid-UV Photoabsorption Cross Sections Of Thin Films Of Glycine And Alanine: Application To Their Photochemistry In The Solar System

A Review Of The Geochemical Environment at Selk Crater on Titan: Applications to Dragonfly

A Breath Of Fresh Air: Oxygen Enhancement From Silicate Sublimation During Early Protostellar Evolution