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Specific kind of search (specialized equipment / search strategies)

General kind of search (general purpose observations / archival data)

Specific technosignature�search

Narrowband radio search��Laser pulses��Echoes from solar system objects

Dyson spheres (IR, optical light curves)��Disappearing stars��Interstellar probes (unusual spectra, nonzero lightness number)

General anomaly search

General radio search (e.g. machine learning at BL)

“Generalized SETI”:�Find weird stuff; “is it aliens?”

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Dyson’s First Law of SETI Investigations

“Every search for alien civilizations should be planned to give interesting results even when no aliens are discovered.”

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Search Upper Limit

Anomaly Threshold

SETI Candidates, Extreme Natural Objects

Most Natural Objects

No Objects

Strength of technosignature signal

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Artificial SS objects

  • Need not be unbound to solar system!
  • Strange spectra/colors
  • Non-gravitational acceleration
    • Measurable lightness number
    • Sudden changes in trajectory
      • Need an alert: well-characterized object is unexpectedly “lost”
      • Need an alert: “new” object becomes characterized but is missing from precovery images
      • Smoking gun: “new” object had close encounter with “lost” object.

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