Optical SETI at ESO in the 2040s

TL;DR

This paper proposes an optical SETI strategy for ESO in the 2040s, leveraging high-multiplex spectroscopic surveys to search for technosignatures in the form of monochromatic laser emissions appearing as unresolved spectral lines. It argues that ESO's 4MOST and the planned Wide-field Spectroscopic Telescope (WST) provide the natural infrastructure to run a parallel SETI program with wide sky coverage and rapid data processing, requiring capabilities in multiplexity, cadence, spectral resolution, and real-time analysis. The work outlines concrete requirements and a development path, emphasizing synergy with existing and future facilities and the strong outreach potential of public engagement around a bold question about life beyond Earth. If successful, this approach offers a scalable, near-term route to detecting intelligent civilizations and generating broad public interest in astronomy and the scientific method.

Abstract

The searches for other life and for intelligence are fundamental problems that science faces today. Most searches so far have been focused on radio, but optical laser communication is an alternative, well suited for a ground-based observatory. A project to search for artificial laser communications with the current and future extreme multiplexity spectroscopic facilities that ESO may develop by the 2040s is outlined. The monochromatic light is a clearly identifiable technosignature. The enormous corollary outreach potential of this initiative is underlined.