SETI & Technosignatures

A Glint In The Eye: Photographic Plate Archive Searches For Alien Visitations

By Keith Cowing
October 28, 2021
Filed under
A Glint In The Eye: Photographic Plate Archive Searches For Alien Visitations
Illumination of satellites. Satellites are only visible when the Sun illuminates them and the sky is not too bright. The higher the altitude of the orbit, the longer the satellite is outside the shadow of the Earth.

An advanced extraterrestrial civilisation that has discovered the Earth might have sent probes here. In this paper, we present a simple strategy to identify Non-Terrestrial artefacts (NTAs) in geosynchronous Earth orbits (GEOs).

We show that even the small pieces of reflective debris in orbit around the Earth can be identified through searches for multiple transients in old photographic plate material exposed before the launch of first human satellite in 1957.

In order to separate between possible false point-like sources on photographic plates from real reflections, we include calculations to show that at least four or five point sources along a line within a 10βˆ—10 arcmin2 image box are a good indicator of NTAs, corresponding to significance levels of 2.5 and 3.9Οƒ. The given methodology will be used to set an upper limit to the prevalence of NTAs with reflective surfaces in geosynchronous orbits.

Beatriz Villarroel, Lars Mattsson, Hichem Guergouri, Enrique Solano, Stefan Geier, Onyeuwaoma Nnaemeka Dom, Martin J. Ward

Comments: Submitted to International Journal of Astrobiology. Comments welcome
Subjects: Popular Physics (physics.pop-ph); Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2110.15217 [physics.pop-ph] (or arXiv:2110.15217v1 [physics.pop-ph] for this version)
Submission history
From: Beatriz Villarroel
[v1] Wed, 6 Oct 2021 14:05:46 UTC (2,284 KB)
Astrobiology, SETI,

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) πŸ––πŸ»