Mercury's Hollows: A Potential Signature of Sulfur Exosphere‐Subsurface Transport
Abstract Bright geological formations called hollows were observed at Mercury and are mostly found in impact craters. While their composition is unknown, subsurface sulfur could be responsible for their formation. Mercury's porous surface favors the subsurface diffusion of returning exospheric atoms. With time, diffusing atoms could form reservoirs in Mercury's subsurface. We use a 3‐D Exospheric Global Model (EGM) including subsurface diffusion to study the evolution of sulfur and sodium in Mercury's subsurface. We identify similar spatial distributions of the sulfur reservoir and of the hollows, but no relationship in the case of sodium. EGM predicts that the longitudinal distribution of hollows correlates with the peak subsurface S column density, ∼60° west of each “hot longitude.” Deeper reservoirs at Mercury's hot poles are predicted, potentially explaining the larger hollows found in these regions. The subsurface diffusion could continuously replenish the sulfur reservoir that could be responsible for the formation of hollows.
Authors
- Giovanni Munaretto (ORCID: https://orcid.org/0000-0001-7904-2657)
- S. Verkercke (ORCID: https://orcid.org/0000-0002-1966-6553)
- Emma Caminiti (ORCID: https://orcid.org/0000-0003-2470-2392)
- Michael Phillips (ORCID: https://orcid.org/0000-0001-8873-2238)
- Liam S. Morrissey (ORCID: https://orcid.org/0000-0001-7860-9957)
- Jean‐Yves Chaufray (ORCID: https://orcid.org/0000-0003-1931-124X)
- François Leblanc (ORCID: https://orcid.org/0000-0002-5548-3519)
Institutions
- Centre National de la Recherche Scientifique (FR)
- Planetary Science Institute (US)
- Memorial University of Newfoundland (CA)
- American Museum of Natural History (US)
- University of Arizona (US)
- Université de Versailles Saint-Quentin-en-Yvelines (FR)
- Japan Aerospace Exploration Agency (JP)
- Sorbonne Université (FR)
- Institute of Space and Astronautical Science (JP)
- Laboratoire atmosphères, milieux, observations spatiales (FR)
- Osservatorio Astronomico di Padova (IT)
- Université Paris 1 Panthéon-Sorbonne (FR)
Publication Details
- Journal
- Geophysical Research Letters
- Published
- 2025-12-17
- DOI
- https://doi.org/10.1029/2025gl118112
- Primary Topic
- Planetary Science and Exploration
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Agence Nationale de la Recherche
- Centre National d’Etudes Spatiales