Katana VentraIP

Active SETI

Active SETI (Active Search for Extra-Terrestrial Intelligence) is the attempt to send messages to intelligent extraterrestrial life. Active SETI messages are predominantly sent in the form of radio signals. Physical messages like that of the Pioneer plaque may also be considered an active SETI message. Active SETI is also known as METI (Messaging to Extra-Terrestrial Intelligence). [1][2]

Not to be confused with METI (Messaging Extraterrestrial Intelligence).

Rationale for METI[edit]

In the paper Rationale for METI,[14] transmission of the information into the Cosmos is treated as one of the pressing needs of an advanced civilization. This view is not universally accepted, and it is not agreed with by those who are against the transmission of interstellar radio messages, but at the same time are not against SETI searching. Such duality is called the SETI Paradox.[15][16]

(1962)[22]

The Morse Message

(1974)

Arecibo Message

1 (1999)

Cosmic Call

(2001)

Teen Age Message

2 (2003)

Cosmic Call

(2008)

Across the Universe

(2009)

Hello from Earth

Reply (2012)[23]

Wow!

(2013)

Lone Signal

(2016)

A Simple Response to an Elemental Message

The below projects have targeted stars between 17 and 69 light-years from the Earth. The exception is the Arecibo message, which targeted globular cluster M13, approximately 24,000 light-years away. The first interstellar message to reach its destination was the Altair (Morimoto - Hirabayashi) Message, which likely reached its target in 1999.[21]

Beacon proposals[edit]

One proposal for a 10 billion watt interstellar SETI beacon was dismissed by Robert A. Freitas Jr. as being infeasible for a pre-Type I civilization, such as humanity, on the Kardashev scale.[54] However, this 1980s technical argument assumes omni-directional beacons, which may not be the best way to proceed on many technical grounds. Advances in consumer electronics have made possible transmitters that simultaneously transmit many narrow beams, covering the million or so nearest stars but not the spaces between.[55] This multibeam approach can reduce the power and cost to levels that are reasonable with early 21st century Earth technology.


Once civilizations have discovered each other's locations, the energy requirements for maintaining contact and exchanging information can be significantly reduced through the use of highly directional transmission technologies. To this end, a 2018 study estimated a 1-2 megawatt infrared laser focused through a 30-45 meter telescope could be seen from about 20,000 light years away.[56]

Communication with extraterrestrial intelligence

 – Organization conducting active SETI

METI (Messaging Extraterrestrial Intelligence)

 – Public conventions on the search for extraterrestrial intelligence

SETIcon

SETI@home

Wow! signal

Interstellar Radio Messages

Archived 2010-09-30 at the Wayback Machine

ActiveSETI.org

active-seti.info

Making a Case for METI

Self-Decoding Messages

Should We Shout Into the Darkness?

Error Correction Schemes In Active SETI

The Evpatoria Messages

Encounter 2001 Message

Zaitsev, Alexander L. (2011). "METI: Messaging to ExtraTerrestrial Intelligence". Searching for Extraterrestrial Intelligence. The Frontiers Collection. pp. 399–428. :10.1007/978-3-642-13196-7_21. ISBN 978-3-642-13195-0.

doi

The Pros and Cons of METI from Centauri Dreams

Zaitsev, Alexander (2012). "Classification of interstellar radio messages". Acta Astronautica. 78: 16–19. :2012AcAau..78...16Z. doi:10.1016/j.actaastro.2011.05.026.

Bibcode

Lone Signal