# Technosignature · Concept

> Any observable sign of technology beyond Earth.

Source: https://mysteriesdept.com/concepts/CPT0DECW03KAJAY/technosignature  
Publisher: Mysteries Department  
Licence: CC BY 4.0 (credit Mysteries Department and link the page)  

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[Concepts](https://mysteriesdept.com/concepts)Technosignature

Concept · astronomy · in 4 mysteries

# Technosignature

Any observable sign of technology beyond Earth.

[Wow! signal](https://mysteriesdept.com/mysteries/wow-signal)[1I/'Oumuamua](https://mysteriesdept.com/mysteries/oumuamua)[HD 139139, the "Random Transiter"](https://mysteriesdept.com/mysteries/hd-139139-random-transiter)

A signal, structure or chemical that would not occur without technology: a narrowband radio signal, a star dimmed by something built, an atmosphere with industrial gases. The Wow! signal is the best-known candidate; every candidate on this site is judged against the natural accounts first, because a technosignature is what is left when those fail.

## Where it comes up

**[Wow! signal](https://mysteriesdept.com/mysteries/wow-signal)**

The Ohio State University Radio Observatory was built by John Kraus between 1956 and 1963 and used for the Ohio Sky Survey until 1971; from 1973 it was given over to SETI, a programme led by Robert Dixon that ran until…

[Q: What does the rest of the Ohio SETI archive say about the signal's statistical company?](https://mysteriesdept.com/mysteries/wow-signal/questions/QST0CXZ4PVE087H/what-does-the-rest-of-the-ohio-seti-archive-say-about-the)[Ohio State University SETI archive (digitised punch cards and tapes, 1973–1998)](https://mysteriesdept.com/datasets/DAT0CXZ504A40JY/ohio-state-university-seti-archive-digitised-punch-cards-and)

**[1I/'Oumuamua](https://mysteriesdept.com/mysteries/oumuamua)**

[Breakthrough Listen Green Bank data on 'Oumuamua, 13 December 2017](https://mysteriesdept.com/datasets/DAT0CSKCTRA1HK2/breakthrough-listen-green-bank-data-on-oumuamua-13-december)

**[HD 139139, the "Random Transiter"](https://mysteriesdept.com/mysteries/hd-139139-random-transiter)**

Two short notes have proposed other scenarios , and a radio search for technosignatures has been made ; these are the published follow-ups.

**[Tabby's star (KIC 8462852)](https://mysteriesdept.com/mysteries/tabbys-star)**

Radio and optical searches for technosignatures found nothing: no narrowband radio signal above 180 to 300 Jy in a 1 Hz channel between 1 and 10 GHz and no optical laser pulses .

## Cite it

```
Mysteries Department. (2026). Technosignature [Concept CPT0DECW03KAJAY]. https://mysteriesdept.com/r/CPT0DECW03KAJAY
```

Key

**CPT** 0DECW03KAJAY

Record

Concept

Field

Astronomy

Related

[Dyson sphere](https://mysteriesdept.com/concepts/CPT0DECW03DJM9T/dyson-sphere) · [Narrowband signal](https://mysteriesdept.com/concepts/CPT0DECW03SJNS9/narrowband-signal)

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[ Wikidata](https://www.wikidata.org/wiki/Q7692902)

**How this page is made.** The definition is the site's, in its own words. “Where it comes up” is read from the answers, methods and evidence that name the concept.

Related concepts

[Dyson sphere](https://mysteriesdept.com/concepts/CPT0DECW03DJM9T/dyson-sphere)[Narrowband signal](https://mysteriesdept.com/concepts/CPT0DECW03SJNS9/narrowband-signal)

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