OKAYAMA UNIVERSITY Archives - Astrobiology

The solid curve represents the average dissolved oceanic Ni concentration (nmol L−1). Light blue indicates pO2 (Present Atmospheric Level, PAL). Changes in urea concentration are indicated by a red gradient (darker red represents higher concentrations). The average dissolved oceanic Ni concentration is plotted on data from ref. 26, and the Oxygen evolution curve is from ref. 1. Solar Lyman α flux is from ref. 83. -- Nature

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Gaia - Planetary Perspectives, Habitable Zones, Origin & Evolution of Life, Press Release, Water/Hycean Worlds & Oceanography

Earth’s Oxygen Boom: A Fresh Perspective For A Billion-year-old Problem

by Keith CowingOctober 10, 2025October 10, 2025

The appearance of oxygen in Earth’s atmosphere was a turning point in the history of our planet, forever transforming the environment and setting the stage for complex life. This event, […]

Mars craterfill deposits showing varying intensities and topographies

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Desert Worlds, Habitable Zones, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Mars, Press Release, Water/Hycean Worlds & Oceanography

Mars Crater Deposits Reveal A History Of Shrinking Ice Volumes Through Ages

by Keith CowingOctober 10, 2025October 10, 2025

For decades, scientists have been curious about how much water Mars once had and what led to its gradual transformation into the dry planet we see today.

Closed diamonds: this study (pyrolite composition at fO2 = IW + 2.0), including ±50 °C uncertainties (described in the note of Table 1); open diamonds: Ishii et al.19 (minimum solidus temperatures, indicated by the red arrows, for a pyrolite composition at estimated IW − 1.2); open circles: Herzberg et al.17 (KLB-1 peridotite composition, estimated IW − 1.2); open squares: Andrault et al.20 (chondritic mantle composition, oxygen fugacity not determined but more oxidized than IW − 1.2); crosses: Pierru et al.22 (pyrolitic mantle composition, oxygen fugacity estimated to be about IW + 2). All data are presented as mean values with ± standard errors (the latter when provided by the authors; Source Data Fig. 1). Dashed lines show predicted solidi at fO2 conditions invoked in siderophile element-based core formation models (IW − 1, IW − 2 and IW − 4), predicted based on equation (1). -- Okayama University

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Lava / magma ocean / Volcanic Worlds, Press Release, Water/Hycean Worlds & Oceanography

Uncovering The Role Of Oxygen Concentration In The Formation Of Early Earth Magma Ocean

by Keith CowingAugust 28, 2024August 27, 2024

It is widely accepted that the early Earth largely consisted of molten magma, forming a global ocean of magma. This extreme state of Earth was likely caused by the intense […]

A representative texture of the Ryugu particle (A0022). (a) An optical image of an entire view of the particle. The rough and irregular surface is finely cracked, resulting in the particle being fragile in nature. (b) A back-scattered electron image of a cross section of the particle. Several µm to 10’s of µm-sized carbonates (mainly dolomite), Fe-oxides (e.g., magnetite), and Fe-sulfides (e.g., pyrrhotite) are widespread in the phyllosilicate-dominated matrix (smectite and serpentine), which also includes sub-µm-sized organic matter, Fe-sulfide, carbonate, and phosphate minerals. -- Okayama University

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Genomics, Proteomics, Bioinformatics, Origin & Evolution of Life, Press Release

How Were Amino Acids Formed Before The Origin Of Life On Earth?

by Keith CowingApril 5, 2023April 5, 2023

Our solar system formed from a molecular cloud, which was composed of gas and dust that was emitted into the interstellar medium (ISM), a vast space between stars. On collapse […]

Origin & Evolution of Life

Novel Insights Into The Evolutionary Link Between Amphibian And Mammalian Peptides

by Keith CowingAugust 23, 2021

In evolutionary biology, tracing back ancestral genetic elements is a quest in reconstructing the history of life on earth. The presence of similar or “homologous” genes in different species speaks […]