The inferred abundance of interstellar objects of technological origin

Abstract

Interstellar objects discovered crossing through the solar system can either be natural objects or technological artifacts from extraterrestrial civilizations. Evidence from our own civilization suggests that early-stage technological civilizations are already able to launch artificial objects beyond their star system, and early-state to late-stage technological civilizations in the Milky Way may have an interest in exploring potentially habitable regions throughout the galaxy. Based on our rate of detection for both natural and artificial populations of interstellar objects, we can estimate their respective local number densities and the total quantity of such objects bound by the Milky Way thin disk. We propose a model for calculating the quantity of such objects based on their observed velocity and number density. We consider the relevance of our model given several detections of interstellar objects over the past decade, and we discuss the implications of the estimated quantity of both natural and artificial objects for understanding their nature and origin.