Magrathea Archives

Planets composed of iron, rock, and water. Illustrations not to scale. The planet model on the left-hand side develops a shallow layer of pure water, while the majority of the water is locked in the rock (”mixed”). The model on the right-hand side is assumed to have a three-layer structure (”separated”). The physical properties of the structures are shown in Figure 3. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Ice Giant, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

The Uncertainty In Water Mass Fraction Of Wet Planets

by Keith CowingJanuary 8, 2026January 8, 2026

Planets with masses between Earth and Neptune often have radii that imply the presence of volatiles, suggesting that water may be abundant in their interiors. However, directly observing the precise […]

Population A: overview of the distributions of Magrathea systems in the parameter space. Solid histograms represent the Magrathea parameters at one Hubble time, while the dashed lines show their initial distributions. The "out" subscript denotes the planetary parameters (blue distributions). The dotted grey lines, instead, show the initial distributions for the whole population, not restricted to the Magratheas. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Status Report

Statistics of Magrathea Exoplanets Beyond The Main Sequence. Simulating The Long-term Evolution Of Circumbinary Giant Planets With TRES

by Keith CowingJuly 8, 2023July 8, 2023

Notwithstanding the tremendous growth of the exoplanetary field in the last decade, limited attention has been paid to the planets around binary stars. Circumbinary planets (CBPs) have been discovered primarily […]