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  • Featured in Physics
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Gardening on the Moon: An Advection-Diffusion Model to Guide the Search for Supernova Debris in the Lunar Regolith

Emily S. Costello*

John Ellis

Brian D. Fields

Rebecca Surman

Xilu Wang

  • Theoretical Particle Physics and Cosmology Group, Department of Physics, King’s College London, London WC2R 2LS, United Kingdom and Theoretical Physics Department, CERN, CH-1211 Geneva 23, Switzerland

  • Departments of Astronomy and of Physics, and Illinois Center for the Advanced Study of the Universe, University of Illinois, Urbana, Illinois 61801, USA

  • *Contact author: costello@higp.hawaii.edu
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Phys. Rev. Lett. 137, 071005 – Published 14 August, 2026

DOI: https://doi.org/10.1103/14kh-nkgl

Abstract

The vertical redistribution of materials in the lunar regolith—ranging from continuously produced space-weathering products to sporadic pulses of supernova- or kilonova-derived isotopes—remains a fundamental problem in planetary science. We present a unified stochastic model of regolith gardening induced by the impact flux. Treating gardening as a competition between impact-driven advection and diffusion predicts the maturity profiles of Apollo cores over more than 2 orders of magnitude in time (1.4×107 to 4.5×108  yr). This model describes well the depth profiles of live Fe60 in Apollo regolith samples, suggesting that supernova dust capture is independent of native iron abundance, and is consistent with a uniform influx at the latitudes of the Apollo landing sites. We extend our model to predict lunar signals for live r-process species that might originate from supernovae or kilonovae: Pu244 tied to terrestrial detections, and I129, Hf182, and Cm247 based on r-process calculations. The Pu244/Fe60 depth profile can probe the origin of Pu244, motivating searches in Artemis regolith samples down to depths O(100)  cm.

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Physics Subject Headings (PhySH)

Focus

Decoding the History Recorded in Lunar Soil

Published 14 August, 2026

A model that captures how crater-forming impacts redistribute lunar dirt will help researchers read the cosmic timeline found in samples returned from the Moon.

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Outline

Information

Phys. Rev. Lett. 137, 071005– Published 14 August, 2026
  • Received 18 April 2026
  • Revised 8 June 2026
  • Accepted 12 June 2026
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