Message To Extra-Terrestrial Intelligence

Active SETI (Active Search for Extra-Terrestrial Intelligence) are attempts 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). Whether humans should engage in Active SETI is controversial due to concerns about potential impacts of extraterrestrial contact, sparking a vigorous policy debate.

History

'Active SETI' was a term as early as 2005, though some decades after the term SETI. The term METI was coined in 2006 by Russian scientist Alexander Zaitsev, who proposed a subtle distinction between Active SETI and METI:

Concern over METI was raised by the science journal ''Nature'' in an editorial in October 2006, which commented on a recent meeting of the International Academy of Astronautics SETI study group. The editor said, "It is not obvious that all extraterrestrial civilizations will be benign, or that contact with even a benign one would not have serious repercussions". In the same year, astronomer and science fiction author David Brin expressed similar concerns. In 2013 Brin amended his initial article based on the recent developments in METI.

In 2010, Douglas A. Vakoch from SETI Institute, addressed concerns about the validity of Active SETI alone as an experimental science by proposing the integration of Active SETI and Passive SETI programs to engage in a clearly articulated, ongoing, and evolving set of experiments to test various versions of the Zoo hypothesis, including specific dates at which a first response to messages sent to particular stars could be expected.

On 13 February 2015, scientists including Douglas Vakoch, David Grinspoon, Seth Shostak, and David Brin at an annual meeting of the American Association for the Advancement of Science discussed Active SETI, and whether transmitting a message to possible intelligent extraterrestrials in the Cosmos was a good idea. That same week, a statement was released, signed by many in the SETI community including Berkeley SETI Research Center modulation scheme was used, most of the time the signal was on the “0” frequency. In addition, “0” tended to be sent in long stretches, which appeared as white lines in the message.

Realized projects

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.

* The Morse Message (1962)
* Arecibo Message (1974)
* Cosmic Call 1 (1999)
* Teen Age Message (2001)
* Cosmic Call 2 (2003)
* Across the Universe (2008)

Hello from Earth
(2009)
* Wow! Reply (2012)
* Lone Signal (2013)
* A Simple Response to an Elemental Message (2016)
The choice of targets, transmission rate, and encoding may effect how likely a message will be received and interpreted by extraterrestrial intelligence. "Across the Universe" and " A Simple Response to an Elemental Message" were sent to Polaris, which is 431 light years distant from us and whose planetary system, even if it exists, may not be suited for life, because it is a supergiant star, spectral type F7Ib which is only 70 million years old. In addition, both transmission rates were very high, about 128 kbit/s, for such moderate transmitter power (about 18 kW). The main defect of the "Hello From Earth" is an insufficient scientific and technical justification, since no famous SETI scientist made statements with validation of HFE's design. As it follows fro

''"After the final message was collected on Monday 24 August 2009, messages were exported as a text file and sent to NASA's Jet Propulsion Laboratory in California, where they were encoded into binary, packaged and tested before transmission"'', but nobody explained why he hopes that such encoded and packaged text will be understood and conceived by possible extraterrestrials.

Transmissions

Below is a table of messages sent and target/destination stars, ordered chronologically by date of sending:

Controversy

Whether or not to conduct Active SETI, as well as the tone of any message, is a highly controversial topic. Active SETI has primarily been criticized due to the perceived risk of revealing the location of the Earth to alien civilizations, without some process of prior international consultation. That is, Active SETI does not meet the criteria for informed consent in a mass experiment involving human subjects and, potentially, nonhuman sentient subjects.

Active SETI is discussed in terms of the ethics of space policy. Issues include whether to send belligerent versus defensive messages, cosmopolitanism, communicative burden, consensus, messaging content, proscriptions on premature messaging, responsibility, and shared values, with concerns that even if successful, humanity could be reduced to a cargo cult. David Brin also urged for an extensive international consultation before any METI activities and has debunked key rationalizations for active SETI (METI), such as the "barn door" argument (unintentional "leaked signals" were millions-fold weaker than intentional METI signals), ignoring/dismissing the precautionary principle (that requires taking extreme precaution e.g. handling extraterrestrial samples even without any known example of risks), and treating METI as being prayer-like which disregards the issue of informed consent from other people. Notable among METI's critics was Stephen Hawking. Hawking, who in his book ''A Brief History of Time'' suggests that "alerting" extraterrestrial intelligences to our existence is foolhardy, citing humankind's history of treating its own kind harshly in meetings of civilizations with a significant technology gap, e.g., the extermination of Tasmanian aborigines. He suggested, in view of this history, that we "lay low". Scientist and science fiction author David Brin expressed similar concerns. Similarly, Liu Cixin's trilogy of novels The Three Body Problem highlights the potential dangers of METI.

However, some scientists consider these fears about the dangers of METI as panic and irrational superstition; Russian and Soviet radio engineer and astronomer Alexander L. Zaitsev has argued against these concerns. Zaitsev argues that we should consider the risks of not attempting to contact extraterrestrial civilizations, since the knowledge and wisdom an ETI could impart to us would save us from humanity's self-destructive tendencies. Similarly, in a March 2015 essay astronomer Seth Shostak considered the risk and ended by stressing that any danger was hypothetical and that humanity would better off risk contact than "endlessly tremble at the sight of the stars".

Astronomer Jill Tarter also disagrees with Hawking, arguing that aliens developed and long-lived enough to communicate and travel across interstellar distances would have evolved a cooperative and less violent intelligence. She however thinks it is too soon for humans to attempt active SETI and that humans should be more advanced technologically first but keep listening in the meantime.

To lend a quantitative basis to discussions of the risks of transmitting deliberate messages from Earth, the SETI Permanent Study Group of the International Academy of Astronautics adopted in 2007 a new analytical tool, the San Marino Scale. Developed by Prof. Ivan Almar and Prof. H. Paul Shuch, the San Marino Scale evaluates the significance of transmissions from Earth as a function of signal intensity and information content. Its adoption suggests that not all such transmissions are created equal, thus each must be evaluated separately before establishing a blanket international policy regarding Active SETI.

In 2012, Jacob Haqq-Misra, Michael Busch, Sanjoy Som, and Seth Baum argued that while the benefits of radio communication on Earth likely outweigh the potential harms of detection by extraterrestrial watchers, the uncertainty regarding the outcome of contact with extraterrestrial beings creates difficulty in assessing whether or not to engage in long-term and large-scale METI.

In 2015, in the context of the Zoo Hypothesis, biologist João Pedro de Magalhães proposed transmitting an invitation message to any extraterrestrial intelligences watching us already and inviting them to respond, arguing this would not put us in any more danger than we are already if the Zoo Hypothesis is correct.

Douglas Vakoch, president of METI, argues that passive SETI itself is already an endorsement of active SETI, since "If we detect a signal from aliens through a SETI program, there's no way to prevent a cacophony of responses from Earth."

In the context of potentially detected extraterrestrial activity on Earth, physicist Mark Buchanan argued that humanity needs to determine whether it would be safe or wise to attempt to communicate with extraterrestrials and work on ways to handle such attempts in an organized manner.

Beacon proposals

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.
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. 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.

See also

* Communication with extraterrestrial intelligence
* Dark forest hypothesis, the idea that planetary civilizations remain silent to avoid the possibility of contact with potentially aggressive worlds
* Detecting Earth from distant star-based systems
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* SETI@home
* Wow! signal

References

External links

Interstellar Radio Messages

ActiveSETI.org


active-seti.info





Should We Shout Into the Darkness?

Error Correction Schemes In Active SETI

The Evpatoria Messages


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The Pros and Cons of METI from Centauri Dreams
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Lone Signal

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Technology in society