Astrochemistry

The Rapid Formation of Macromolecules in Irradiated Ice of Protoplanetary Disk Dust Traps

By Keith Cowing
Status Report
astro-ph.EP
January 23, 2025
Filed under , , , , , , , ,
The Rapid Formation of Macromolecules in Irradiated Ice of Protoplanetary Disk Dust Traps
Schematic depiction of the IOM formation scenario. Grains with pristine, simple ice components (1) radially drift into the protoplanetary disk (2) and migrate to the dust trap hotspot through vertical mixing/transport (3), where heavy irradiation of the luke-warm ice results in the formation of organic macromolecular matter (4). — astro-ph.EP

Organic macromolecular matter is the dominant carrier of volatile elements such as carbon, nitrogen, and noble gases in chondrites — the rocky building blocks from which Earth formed. How this macromolecular substance formed in space is unclear.

We show that its formation could be associated with the presence of dust traps, which are prominent mechanisms for forming planetesimals in planet-forming disks. We demonstrate the existence of heavily irradiated zones in dust traps, where small frozen molecules that coat large quantities of microscopic dust grains could be rapidly converted into macromolecular matter by receiving radiation doses of up to several 10s of eV molecule−1 year−1.

This allows for the transformation of simple molecules into complex macromolecular matter within several decades. Up to roughly 4% of the total disk ice reservoir can be processed this way and subsequently incorporated into the protoplanetary disk midplane where planetesimals form.

This finding shows that planetesimal formation and the production of organic macromolecular matter, which provides the essential elemental building blocks for life, might be linked.

Niels F. W. Ligterink, Paola Pinilla, Nienke van der Marel, Jeroen Terwisscha van Scheltinga, Alice S. Booth, Conel M. O’D. Alexander, My E. I. Riebe

Comments: 16 pages, 5 figures, Accepted in Nature Astronomy 10 July 2024, Published 30 July 2024
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2501.10512 [astro-ph.EP] (or arXiv:2501.10512v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2501.10512
Focus to learn more
Journal reference: Nature Astronomy 8.10 (2024): 1257-1263
Related DOI:
https://doi.org/10.1038/s41550-024-02334-4
Focus to learn more
Submission history
From: Niels Ligterink
[v1] Fri, 17 Jan 2025 19:13:08 UTC (649 KB)
https://arxiv.org/abs/2501.10512
Astrobiology,

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) 🖖🏻