SETI & Technosignatures

The Case for Technosignatures: Why They May Be Abundant, Long-lived, Highly Detectable, and Unambiguous

By Keith Cowing
March 23, 2022
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The Case for Technosignatures: Why They May Be Abundant, Long-lived, Highly Detectable, and Unambiguous

The intuition suggested by the Drake equation implies that technology should be less prevalent than biology in the galaxy.

However, it has been appreciated for decades in the SETI community that technosignatures could be more abundant, longer-lived, more detectable, and less ambiguous than biosignatures.

We collect the arguments for and against technosignatures’ ubiquity and discuss the implications of some properties of technological life that fundamentally differ from nontechnological life in the context of modern astrobiology: It can spread among the stars to many sites, it can be more easily detected at large distances, and it can produce signs that are unambiguously technological. As an illustration in terms of the Drake equation, we consider two Drake-like equations, for technosignatures (calculating N(tech)) and biosignatures (calculating N(bio)).

We argue that Earth and humanity may be poor guides to the longevity term L and that its maximum value could be very large, in that technology can outlive its creators and even its host star. We conclude that while the Drake equation implies that N(bio)>>N(tech), it is also plausible that N(tech)>>N(bio). As a consequence, as we seek possible indicators of extraterrestrial life, for instance, via characterization of the atmospheres of habitable exoplanets, we should search for both biosignatures and technosignatures.

This exercise also illustrates ways in which biosignature and technosignature searches can complement and supplement each other and how methods of technosignature search, including old ideas from SETI, can inform the search for biosignatures and life generally.

Jason T. Wright, Jacob Haqq-Misra, Adam Frank, Ravi Kopparapu, Manasvi Lingam, Sofia Z. Sheikh

Comments: Published in ApJ Letters
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM); Cryptography and Security (cs.CR); Popular Physics (physics.pop-ph)
Cite as: arXiv:2203.10899 [astro-ph.EP] (or arXiv:2203.10899v1 [astro-ph.EP] for this version)
Journal reference: 2022 ApJL 927 L30
Submission history
From: Jason Wright
[v1] Mon, 21 Mar 2022 11:48:24 UTC (108 KB)

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) 🖖🏻