A research proposal by Ana Henrique, Sofia Sheikh and Benjamin Fields asks whether the landscapes of other worlds could preserve recognizable traces of technological activity. Posted to arXiv on October 20, 2026, and highlighted by Astrobiology on November 2, the paper is a proposed search programme. It reports no confirmed extraterrestrial structure.

What the proposal adds

The authors draw an analogy with lasting human alterations to Earth's terrain. They suggest examining planetary imagery with both supervised methods trained on known patterns and anomaly detectors that flag unfamiliar features. Their proposed follow-up combines observations such as spectroscopy and subsurface measurements. The stated ambition includes quantitative limits on how common detectable surface technosignatures could be.

This is a broader agenda than the lunar anomaly-recovery work covered in our earlier report. It discusses how to design searches across different terrain and how to investigate candidate features; it does not announce another successful recovery experiment. The arXiv posting itself is not evidence of completed peer review.

A real camera supplies a useful reality check

NASA's Mars Reconnaissance Orbiter instrument description distinguishes individual HiRISE pixels, typically about 30–60 centimetres at the listed operating altitudes, from resolved surface features, roughly 1.3–2.4 metres across. A pixel's ground size is not a guarantee that an object that small can be identified. NASA documents imaging capability; it does not endorse an alien interpretation of any particular landform.

That distinction affects an eventual survey's conclusions. A search should state the smallest feature it could reliably detect, the terrain and illumination it examined, and how often it mistakes geology for construction. Without those quantities, a count of unusual shapes cannot become a defensible estimate of artificial structures.

Why this matters to UAP research

The connection is methodological, not a claim that lunar or Martian features explain Earth's UAP reports. NASA's 2023 UAP study identifies calibration, metadata, multiple measurements and baseline observations as essential weaknesses to address. Planetary searches face a comparable need to distinguish an algorithm's alert from a physical interpretation.

Our assessment is that the most useful next deliverable would be a reproducible search with documented coverage, known-object controls, false-positive rates and a follow-up process. A null result would also be informative if its detection limits were stated. Neither visual regularity nor an anomaly score alone establishes deliberate construction.

Source scope: the Astrobiology item points readers to the same proposal and is not an independent replication. We reviewed the paper and NASA documentation; we did not reprocess planetary imagery.

Hero: original AI-generated editorial illustration. The terrain, equipment and screen markings are fictional and are not research evidence.