No evidence for interstellar planetesimals trapped in the Solar System

Abstract

In two recent papers published in MNRAS, Namouni and Morais (2018, 2020) claimed evidence for the interstellar origin of some small Solar System bodies, including i) objects in retrograde co-orbital motion with the giant planets, and ii) the highly-inclined Centaurs. Here, we discuss the flaws of those papers that invalidate the authors' conclusions. Numerical simulations backwards in time are not representative of the past evolution of real bodies. Instead, these simulations are only useful as a means to quantify the short dynamical lifetime of the considered bodies and the fast decay of their population. In light of this fast decay, if the observed bodies were the survivors of populations of objects captured from interstellar space in the early Solar System, these populations should have been implausibly large (e.g. about 10 times the current main asteroid belt population for the retrograde coorbital of Jupiter). More likely, the observed objects are just transient members of a population that is maintained in quasi-steady state by a continuous flux of objects from some parent reservoir in the distant Solar System. We identify in the Halley type comets and the Oort cloud the most likely sources of retrograde coorbitals and highly-inclined Centaurs.

in press in MNRAS

References in corpus (13)

• Debiased orbit and absolute-magnitude distributions for near-Earth objects
• Oort Cloud and Scattered Disc formation during a late dynamical instability in the Solar System
• The Planet Nine Hypothesis
• Origin and Evolution of Short-Period Comets
• Interstellar Interlopers: Number Density and Origins of 'Oumuamua-like Objects
• Reassessing the formation of the inner Oort cloud in an embedded star cluster
• An Oort cloud origin for the high-inclination, high-perihelion Centaurs
• Generation of Highly Inclined Trans-Neptunian Objects by Planet Nine
• An interstellar origin for Jupiter's retrograde co-orbital asteroid
• Identifying Interstellar Objects Trapped in the Solar System through Their Orbital Parameters
• An interstellar origin for high-inclination Centaurs
• Capture of interstellar objects: a source of long-period comets
• OSSOS IXX: Testing Early Solar System Dynamical Models using OSSOS Centaur Detections

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• A halo of trapped interstellar matter surrounding the solar system
• Characterization of Exogenic Boulders on Near-Earth Asteroid (101955) Bennu from OSIRIS-REx Color Images
• The gateway from Centaurs to Jupiter-family Comets: thermal and dynamical evolution
• Capture of interstellar objects II: by the Solar system
• Small solar system objects on highly inclined orbits: Surface colours and lifetimes
• The New Astronomical Frontier of Interstellar Objects
• Dynamical Origin of (469219) Kamo`oalewa of Tianwen-2 Mission from the Main-Belt: ${\nu }_6$ Secular Resonance, Flora Family or 3:1 Resonance with Jupiter
• Activity of the Jupiter co-orbital comet P/2019~LD${}_2$ (ATLAS) observed with OSIRIS at the 10.4 m GTC
• Inclination pathways of planet-crossing asteroids
• On the interstellar origin of high-inclination Centaurs
• Close Encounters of the Interstellar Kind: Examining the Capture of Interstellar Objects in Near Earth Orbit