# Kuiperian Objects and Wandering Cosmic Objects

## TL;DR

This study models interactions between wandering cosmic objects and Kuiper belt objects, explaining the origins of various distant solar system objects and suggesting the Kuiper belt was once much larger, with supporting observational evidence.

## Contribution

It introduces a new dynamical mechanism involving wandering cosmic objects that can produce diverse Kuiper belt-like objects and explains their observed properties.

## Key findings

- Wandering cosmic objects can produce eccentric Kuiper objects similar to observed ETNOs.
- Encounter outcomes can generate different classes of distant objects with specific orbital characteristics.
- Evidence suggests the Kuiper belt was once significantly larger, possibly extending to 90 AU.

## Abstract

We study the effects of an encounter between a wandering cosmic object (WCO) of 0.1 solar mass and some Kuiperian Objects (KO). First, we let the WCO cross the out-skirt of ou Kuiper belt. Such encounters can produce two types of solar objects: Eccentric Kuiper Objects of type I (EKO-I) whose perihelion is comparable to, but always smaller than the aphelion of the initial KO and Eccentric Kuiper Objects of type II (EKO-II) whose perihelion can be as small as a few AU. EKO-I tend to have a fairly large range of eccentricities, but EKO-II tend to have very large eccentricities. Both tend to be produced in clusters similar to those observed in Extreme TransNeptunian Objects (ETNO). When a WCO crosses the path of an EKO-I, it will produce two main classes of objects: Far Kuiper Objects (FKO) of types I and II. The Sednitos discovered in the past years fit the FKO-I class with their large major axis and fairly large eccentricity, while the FKO-II class is different with its large major axis but smaller eccentricity and opposite spinning direction. When a WCO encounters an EKO-II, the latter can remain in the same class, spinning in either direction, it can also en up in the EKO-I class also spinning in either direction, but it can also be sent onto orbits with extremely long semi-major axis, relatively small eccentricity where both spins are allowed. This FKO-III class could be likened to the Lower Oort Cloud Objects as their major axis is a fair fraction of a light-year. These results lead us to consider the possibility that the Kuiper Belt was once substantially larger than it is now, perhaps 90 AU. We find some evidence of this scenario in current astronomical data.