Technosignature Searches of Interstellar Objects

TL;DR

This paper discusses the potential of interstellar objects as targets for technosignature searches, emphasizing the importance of systematic follow-up with upcoming surveys like LSST to detect signs of extraterrestrial technology.

Contribution

It reviews the literature on ISOs as technosignature targets, proposes classes of technosignatures suitable for ISO follow-up, and offers a roadmap for systematic study of these objects.

Findings

ISOs are promising targets for technosignature searches.

Upcoming surveys will increase ISO discoveries, enabling routine examination.

Careful analysis is needed to distinguish technosignatures from natural objects.

Abstract

With the discovery of the third confirmed interstellar object (ISO), 3I/ATLAS, we have entered a new phase in the exploration of these long-predicted objects. Though confirmed discovery of ISOs is quite recent, their utility as targets in the search for technosignatures (historically known as the Search for Extraterrestrial Intelligence -- SETI) has been discussed for many decades. With the upcoming NSF-DOE Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST), the discovery and tracking of such objects is expected to become routine, and thus so must our examination of these objects for possible technosignatures. Here we review the literature surrounding ISOs as targets for technosignatures, which provides a well-developed motivation for such exploration. We outline four broad classes of technosignatures that are well suited for ISO follow-up, including the type of data needed and the best timing for study. Given the limitations in the current understanding of ISOs, we show that care must be taken in identifying technosignatures based primarily on comparison to objects in the Solar System. We therefore provide a roadmap for careful and consistent study of the population of ISOs in the hope of identifying technosignatures.