Habitable Zones

Toward Alternative Earths’ Habitability of Solar System Bodies at Earth’s Orbit

By Keith Cowing

Status Report

astro-ph.EP

September 15, 2025

Filed under astro-ph.EP, atmosphere, exoplanet, greenhouse, habitability

Toward Alternative Earths’ Habitability of Solar System Bodies at Earth’s Orbit — Large enough to retain an atmosphere and drive geologic/hydrologic cycles, but not so massive that relocation is infeasible. This figure illustrates why planet size and escape velocity are critical factors for habitability. It plots the radius of planets (relative to Earth) on the horizontal axis and their escape velocity (in km/s) on the vertical axis. Escape velocity is the minimum speed an object needs to break free from a planet’s gravitational pull. — astro-ph.EP

This paper presents the first structured evaluation of Solar System bodies hypothetically relocated to Earth orbit (1 AU) to assess their potential as alternative habitats.

Using comparative criteria, planetary size and gravity, atmospheric retention, volatile accessibility, weather system potential, soil development feasibility, and orbital transfer cost. We find that most bodies are unsuitable.

Mercury and the Moon lack volatiles and atmospheres, while gas and ice giants offer no solid surfaces. Venus, despite strong atmospheric retention, remains constrained by extreme greenhouse forcing. Mars emerges as the most viable candidate, balancing accessibility and volatile resources.

Titan provides a conditional long-term promise, with a dense atmosphere and rich organics that could transition to a water-based cycle at 1 AU. These findings highlight new pathways for planetary engineering and long-term human survival.

Mohammed Abdel Razak

Comments: 6 pages, 7 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2509.06259 [astro-ph.EP] (or arXiv:2509.06259v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2509.06259
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Submission history
From: Mohammed Abdel Razek
[v1] Mon, 8 Sep 2025 00:53:52 UTC (629 KB)
https://arxiv.org/abs/2509.06259

Astrobiology,

Keith Cowing

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻

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