The refractory-to-ice ratio in comet 67P: Implications on the composition of the comet-forming region of the protoplanetary disk

IF 1.8 4区物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS

Planetary and Space Science Pub Date : 2025-02-18 DOI:10.1016/j.pss.2025.106061

Raphael Marschall , Alessandro Morbidelli , Yves Marrocchi

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引用次数: 0

Abstract

Comets, asteroids, and other small bodies are thought to be remnants of the original planetesimal population of the Solar System. As such, their physical, chemical, and isotopic properties hold crucial details on how and where they formed and how they evolved. Yet, placing precise constraints on the formation region of these bodies has been challenging. Data from spacecraft missions have a particularly high potential of addressing the question of the origin of the visited bodies. ESA’s Rosetta mission to comet 67P/Churyumov-Gerasimenko returned data from the comet for two years on its journey around the Sun. This extensive data set has revolutionized our view on comets and still holds unsolved problems.

Here, we aim to determine comet 67P’s bulk elemental composition from Rosetta data, including its refractory-to-ice ratio. We use these results to constrain the temperature in the protoplanetary disk where comets formed and, using a disk model, the formation location.

We use the Rosetta/ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) measurement of the volatile/ice composition and the Rosetta/COSIMA (COmetary Secondary Ion Mass Analyzer) measurements of the refractory composition of comet 67P. These measurements are combined using a Monte Carlo method. The refractory-to-ice ratio is a free parameter that is constrained a posteriori.

Using only the composition, we constrain the refractory-to-ice ratio to

0.5 < χ < 1.7

, and derive the bulk elemental abundances for 67P of H, C, N, O, Na, Mg, Al, S, K, Ar, Ca, Cr, Mn, Fe, Kr, and Xe. We find the noble gas xenon in near solar elemental abundance in comet 67P. Krypton is slightly depleted, while argon is heavily depleted. Comet 67P is enriched in all three noble gases by up to 2.5 orders of magnitude compared to CI chondrites. We show this is consistent with a formation region between 25 and 35 au in a protoplanetary disk region with temperatures between 30 and 40 K and with the trapping of dust for a long time in rings of the protoplanetary disk.

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来源期刊

Planetary and Space Science 地学天文-天文与天体物理

CiteScore

5.40

自引率

4.20%

发文量

126

审稿时长

15 weeks

期刊介绍： Planetary and Space Science publishes original articles as well as short communications (letters). Ground-based and space-borne instrumentation and laboratory simulation of solar system processes are included. The following fields of planetary and solar system research are covered: • Celestial mechanics, including dynamical evolution of the solar system, gravitational captures and resonances, relativistic effects, tracking and dynamics • Cosmochemistry and origin, including all aspects of the formation and initial physical and chemical evolution of the solar system • Terrestrial planets and satellites, including the physics of the interiors, geology and morphology of the surfaces, tectonics, mineralogy and dating • Outer planets and satellites, including formation and evolution, remote sensing at all wavelengths and in situ measurements • Planetary atmospheres, including formation and evolution, circulation and meteorology, boundary layers, remote sensing and laboratory simulation • Planetary magnetospheres and ionospheres, including origin of magnetic fields, magnetospheric plasma and radiation belts, and their interaction with the sun, the solar wind and satellites • Small bodies, dust and rings, including asteroids, comets and zodiacal light and their interaction with the solar radiation and the solar wind • Exobiology, including origin of life, detection of planetary ecosystems and pre-biological phenomena in the solar system and laboratory simulations • Extrasolar systems, including the detection and/or the detectability of exoplanets and planetary systems, their formation and evolution, the physical and chemical properties of the exoplanets • History of planetary and space research