Astrochemistry

Cosmic-Ray Bath in a Past Supernova Gives Birth to Earth-Like Planets

By Keith Cowing

Status Report

astro-ph.EP

December 15, 2025

Filed under astro-ph.EP, astrochemistry, exoplanet, meteorite, rock exoplanet, short-lived radionuclides, stellar nucleosynthesis, Supernova

Cosmic-Ray Bath in a Past Supernova Gives Birth to Earth-Like Planets — Schematic picture of the system assumed in this study. (a) A supernova explosion occurs at a distance 𝑑 from the protosolar disk, and (b) the expanding supernova shockwave contacts the protosolar disk. At this time, a huge number of accelerated particles are trapped in the shockwave region. With the contact, (c-1) SLRs synthesized inside the supernova are directly injected into the disk, and (c-2) particles trapped inside the shockwave irradiate the disk, causing nucleosynthesis within the disk. — astro-ph.EP

A key question in astronomy is how ubiquitous Earth-like rocky planets are. The formation of terrestrial planets in our solar system was strongly influenced by the radioactive decay heat of short-lived radionuclides (SLRs), particularly 26Al, likely delivered from nearby supernovae.

However, current models struggle to reproduce the abundance of SLRs inferred from meteorite analysis without destroying the protosolar disk. We propose the `immersion’ mechanism, where cosmic-ray nucleosynthesis in a supernova shockwave reproduces estimated SLR abundances at a supernova distance (∼1 pc), preserving the disk.

We estimate that solar-mass stars in star clusters typically experience at least one such supernova within 1 pc, supporting the feasibility of this scenario. This suggests solar-system-like SLR abundances and terrestrial planet formation are more common than previously thought.

Ryo Sawada, Hiroyuki Kurokawa, Yudai Suwa, Tetsuo Taki, Shiu-Hang Lee, Ataru Tanikawa

Comments: 23 pages, 5 figures, 1 table, and Supplementary Materials. Author accepted manuscript of an article published in Science Advances
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); High Energy Astrophysical Phenomena (astro-ph.HE); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2512.09660 [astro-ph.EP] (or arXiv:2512.09660v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2512.09660
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Journal reference: Science Advances (2025)
Related DOI:
https://doi.org/10.1126/sciadv.adx7892
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Submission history
From: Ryo Sawada
[v1] Wed, 10 Dec 2025 13:56:44 UTC (1,263 KB)
https://arxiv.org/abs/2512.09660

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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