Article In: orcid
Effect of asteroid gardening on the exogenous delivery of extraterrestrial organic matter
Earth and Planetary Science Letters
— 2026 — Elsevier
Key information
Authors:
Published in
October 15, 2026
Abstract
Carbonaceous chondrites contain up to 4 wt% organic matter, likely inherited from precursors synthesised during preaccretion events. This organic inventory was later altered by hydrothermal and radiative processes, though the role of shock-induced impacts remains unclear. In this study, we examine the solid-state mechanochemical reactivity of hexamethylenetetramine (HMT) with sodium-rich montmorillonite (MMT) as an analogue to investigate the influence of shock- or impact-induced processes on organic matter evolution. HMT is reactive under mechanical stress, particularly when the clay mineral structure is disrupted, resulting in a wide range of molecules, including HMT-related compounds (as HMT-CH3, HMT-OH, among others), pyrazine and triazinane/triazine derivatives. Notably, the incorporation of oxygen in N-rich species was also observed, despite the absence of liquid water. Conversely, when the clay mineral remains intact, mechanical input promotes the solid-state insertion of HMT-like molecules (as HMT, HMT-CH3 and triazinane derivative) within its interlayer space, thereby protecting it from further reaction. The “cyclic mechanical input” delivered by laboratory milling (i.e., MM 200) and grinding (i.e., McCrone) is relevant to shock processes at an asteroid surface through repeated micrometeorite and IDPs impacts (i.e., space gardening). This work highlights shock/impact as a key factor driving both transformation and protection of extraterrestrial organics, offering new insights on how impact processes might have shaped extraterrestrial organic matter and consequent exogenous delivery of possibly prebiotic compounds to planetary surfaces.
Publication details
Authors in the community:
Gustavo Pinho Maia
ist198548
José Armando Luísa da Silva
ist11950
Publication version
VoR - Version of Record
Publisher
Elsevier
Link to the publisher's version
https://www.sciencedirect.com/science/article/pii/S0012821X26004188
Title of the publication container
Earth and Planetary Science Letters
Volume
692
Fields of Science and Technology (FOS)
chemical-sciences - Chemical sciences
Keywords
- Mechanochemistry
- Asteroid gardening
- Impact events
- Organo/mineral associations
- Organic matter evolution
- HMT
Publication language (ISO code)
eng - English
Rights type:
Only metadata available
Creative Commons license
CC-BY - Attribution
Financing entity
Fundação para a Ciência e a Tecnologia
Funding Stream: FCT – Fundação para a Ciência e a Tecnologia, I.P. (national public funds)
Identifier for the funding entity: https://doi.org/10.13039/501100001871
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: UID/00100/2025
Financing entity
Fundação para a Ciência e a Tecnologia
Funding Stream: FCT – Fundação para a Ciência e a Tecnologia, I.P.; PRR (Plano de Recuperação e Resiliência) funding
Identifier for the funding entity: https://doi.org/10.13039/501100001871
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: UID/PRR/00100/2025
Financing entity
Fundação para a Ciência e a Tecnologia
Funding Stream: FCT – Fundação para a Ciência e a Tecnologia, I.P.; PRR2 funding
Identifier for the funding entity: https://doi.org/10.13039/501100001871
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: UID/PRR2/00100/2025
Financing entity
Fundação para a Ciência e a Tecnologia
Funding Stream: FCT – Fundação para a Ciência e a Tecnologia, I.P. (national public funds)
Identifier for the funding entity: https://doi.org/10.13039/501100001871
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: LA/P/0056/2020
Financing entity
Fundação para a Ciência e a Tecnologia
Title of the project, award or grant: PhD Scholarship (Mix)
Funding Stream: FCT – Fundação para a Ciência e a Tecnologia, I.P. doctoral scholarship funding
Identifier for the funding entity: https://doi.org/10.13039/501100001871
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: 2023.01099.BD
Financing entity
European Research Council
Title of the project, award or grant: HYDROMA – Origin and evolution of organic matter in carbonaceous chondrites: influence of hydrothermal processes
Funding Stream: European Research Council (ERC) funding under the ERC Consolidator Grant (ERC-2018-COG)
Identifier for the funding entity: https://doi.org/10.13039/501100000781
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: 819587
Financing entity
Simons Foundation
Title of the project, award or grant: Simons Foundation SCOL Award
Funding Stream: Simons Foundation grant funding
Identifier for the funding entity: https://doi.org/10.13039/100000893
Type of identifier of the funding entity: Crossref Funder
Number for the project, award or grant: 302497