[astro-ph.IM] Artificial radio emissions have historically been a major focus of technosignature searches.
Here, we apply an anthropological lens to expand this scope to surface technosignatures: non-random, intentional patterning on planetary terrain, similar to long-lasting human-made landscapes and monuments on Earth.
On geologically inactive bodies such as the Moon and Mars, artificial traces and patterns could potentially remain visible for hundreds of millions of years.
We discuss two recent developments that make this search timely: high-resolution imaging datasets, such as those produced by the HiRISE camera on the Mars Reconnaissance Orbiter (MRO), and ML-based anomaly-detection methods.
Finally, we list two possible approaches to developing a model capable of searching for these surface technosignatures: a supervised and an unsupervised one.
Complemented by LiDAR, ground-penetrating radar, and reflectance spectroscopy, these methods would enable the first quantitative upper limits on surface technosignatures while yielding ancillary benefits for planetary science.
Three examples of surface technosignatures on Earth that are over 500 years old and are visible in orbital satellite imagery: 1) Ziggurat of Ur 2) Inca Agricultural Terraces and 3) Pyramid of the Sun. The a) images show the structures from a near-surface perspective while the b) images are representative of the structures appearance in satellite imagery, as sourced from Google Maps. Two takeaways can be drawn here: surface technosignatures can be readily identified from satellite imagery, and we have a large, consistent training dataset of examples of human surface technosignatures from the Earth itself. Image credits: © Ziggurat of Ur: Qahtan Al-Abeed — © Inca Agricultural Terraces: PsamatheM — © Pyramid of the Sun: Burkhard M¨ucke — [astro-ph.IM]
Ana Henrique, Sofia Sheikh, Benjamin Fields
Subjects: Instrumentation and Methods for Astrophysics (astro-ph.IM); Earth and Planetary Astrophysics (astro-ph.EP); Machine Learning (cs.LG)
Cite as: arXiv:2610.28687 [astro-ph.IM] (or arXiv:2610.28687v1 [astro-ph.IM] for this version)
https://doi.org/10.48550/arXiv.2610.28687
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Submission history
From: Ana Henrique Salvan Ph.D.
[v1] Tue, 20 Oct 2026 03:26:56 UTC (2,792 KB)
https://arxiv.org/abs/2610.28687
Astrobiology,
