Work

Sublimation of H 2 O Molecules from Interstellar and Dynamically New Comets: Case Study of 3I/ATLAS

Year: 2026

Type: article

Abstract: Comets are often characterized by their production of H 2 O molecules, whose quantity is further used to constrain the fraction of active area of their nuclei. The latter retrieval is based on a theory developed half century ago. We evaluate it, suggesting improvements in light of more recent models developed to evaluate lunar temperature. We take into account the difference in temperature of the outermost surface layer and the internal volume of the nucleus and the energy exchange between these two parts via thermal emission. The resulting equation takes on a simple form for dynamically new and interstellar comets due to the extremely low temperature of their interior volume. We apply this new approach to the interstellar Comet 3I/ATLAS. The result is a significant increase in the active area of the nucleus needed to reproduce the production of H 2 O molecules observed in Comet 3I/ATLAS.

Source: The Astrophysical Journal

DOI: 10.3847/1538-4357/aeaa5c

Authors: Evgenij Zubko, Gorden Videen, Sungsoo S. Kim

Institutions: University of Helsinki, Space Science Institute, Kyung Hee University

Language: English

Topic: Astro and Planetary Science

Subfield: Space and Planetary Science

Field: Earth and Planetary Sciences

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $4,499

Funders: National Aeronautics and Space Administration, Korea Astronomy and Space Science Institute, Ministry of Science and ICT, South Korea