Assessment of the Mass Loss and Radius Change of 3I/ATLAS Based on Observed Production Rates

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Frincke, Tessa T., Seligman, Darryl Z.
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866917552746135552
author Frincke, Tessa T.
Seligman, Darryl Z.
author_facet Frincke, Tessa T.
Seligman, Darryl Z.
contents Formed from the debris of planet formation, interstellar comets provide invaluable insights into the chemical compositions of planetary systems outside of our Solar System. Spectroscopic observations of 3I/ATLAS, the third interstellar object, reveal production of numerous volatiles and refractory species throughout its trajectory. In this paper we present a framework to calculate the change in radius of an object on an arbitrary trajectory at any point in its orbit, applicable to any small body experiencing mass-loss. We next provide a comprehensive, machine readable table containing volatile and refractory production rates from all reported observations of 3I/ATLAS pre- and post-perihelion. Applying these equations to 3I/ATLAS, we calculate that it has lost $\sim$ 1.05 -- 6.56 meters of its surface during its passage through the Solar System, corresponding to $\sim$ 10$^9$ -- 10$^{10}$ kg and $\sim$ 0.10 -- 1.13% of its total mass. These numbers could be lower estimates if the dust-to-gas ratio of its outflow was sustained at a high level. Conservative and optimistic estimates were calculated over a range of heliocentric distances defined by the onset of activity in reported observations and the typical onset of sublimation distance for each species, respectively. The reported production rates combined with the change in radius calculation can be used to estimate subsurface locations of various species within the nucleus of 3I/ATLAS. Post-perihelion measurements of 3I/ATLAS likely originated from layers which still experienced some level of galactic cosmic ray processing.
format Preprint
id arxiv_https___arxiv_org_abs_2606_01377
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Assessment of the Mass Loss and Radius Change of 3I/ATLAS Based on Observed Production Rates
Frincke, Tessa T.
Seligman, Darryl Z.
Earth and Planetary Astrophysics
Astrophysics of Galaxies
Formed from the debris of planet formation, interstellar comets provide invaluable insights into the chemical compositions of planetary systems outside of our Solar System. Spectroscopic observations of 3I/ATLAS, the third interstellar object, reveal production of numerous volatiles and refractory species throughout its trajectory. In this paper we present a framework to calculate the change in radius of an object on an arbitrary trajectory at any point in its orbit, applicable to any small body experiencing mass-loss. We next provide a comprehensive, machine readable table containing volatile and refractory production rates from all reported observations of 3I/ATLAS pre- and post-perihelion. Applying these equations to 3I/ATLAS, we calculate that it has lost $\sim$ 1.05 -- 6.56 meters of its surface during its passage through the Solar System, corresponding to $\sim$ 10$^9$ -- 10$^{10}$ kg and $\sim$ 0.10 -- 1.13% of its total mass. These numbers could be lower estimates if the dust-to-gas ratio of its outflow was sustained at a high level. Conservative and optimistic estimates were calculated over a range of heliocentric distances defined by the onset of activity in reported observations and the typical onset of sublimation distance for each species, respectively. The reported production rates combined with the change in radius calculation can be used to estimate subsurface locations of various species within the nucleus of 3I/ATLAS. Post-perihelion measurements of 3I/ATLAS likely originated from layers which still experienced some level of galactic cosmic ray processing.
title Assessment of the Mass Loss and Radius Change of 3I/ATLAS Based on Observed Production Rates
topic Earth and Planetary Astrophysics
Astrophysics of Galaxies
url https://arxiv.org/abs/2606.01377