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Making a Case for METI
by Dr. Alexander Zaitsev, Charles M. Chafer, and Richard Braastad

"Intelligent life in the Universe is an extraordinary and rare, perhaps even unique, phenomenon. This fact places an especial responsibility on humankind to ensure that this spark of consciousness does not fade away owing to its unwise actions, but instead flares into a blazing bonfire that could be observed even from the remotest regions of our Galaxy."
Iosif S. Shklovskii, Universe, Life, Mind

Many leaders of the modern SETI community oppose the deliberate transmission of messages from Earth to the stars in attempts to communicate with extraterrestrial intelligence (ETI). Instead, they prefer to take a passive approach called SETI: merely monitoring optical and radio wavelengths for messages sent by an ETI. This attitude is interesting in that, just a few decades ago, SETI was envisioned as a two-way communication process. In fact, the original acronym for the community was CETI for Communication with Extraterrestrial Intelligence.

Today, the deliberate transmission of messages to the stars is often referred to as Active SETI, as opposed, presumably, to Passive SETI, the monitoring approach described above. Other terms have been suggested for Active SETI: BETI, for Broadcast to Extraterrestrial Intelligence, and METI, our preferred acronym, for Messaging to Extraterrestrial Intelligence.

Several METI attempts have been made over the past few decades: the famous 1974 Arecibo message; the Pioneer and Voyager interstellar spacecraft that carry information about Earth for the benefit of whatever ETI may encounter the spacecraft in the future; and the Invitation to ETI Web site where Dr. Allen Tough of the University of Toronto has composed a message inviting ET, whom, Tough presumes, may be monitoring the World Wide Web, to contact us.

Furthermore, the authors of this paper have, collectively, conducted three METI transmissions: Cosmic Call 1999, Teen Age Message 2001, and Cosmic Call 2003, all from the Evpatoria Planetary Radar facility in Ukraine. Like Arecibo, our transmissions include scientific information. But unlike the Arecibo message, which was composed by a handful of scientific elites, our transmissions also include personal messages of thousands of people from around the world. In contrast to many SETI leaders, we strongly believe in a truly democratic approach to METI: that the people themselves, not just a handful of elites, should speak for Earth through their direct participation in METI.

Indeed, public interest in METI is widespread: Our Cosmic Calls have generated worldwide media coverage. Furthermore, many rank-and-file SETI enthusiasts appear to support METI: According to an informal poll on the SETI@home Web site (see As of January 8, 2005, 78% of respondents have answered yes to the question, Should Earth send a signal for aliens to hear?

Yet many of the elites in the SETI community?s leadership remain stubbornly opposed to METI. They cite several arguments. We address three of them here:

1. METI is not scientific.

Quite the contrary, our METI transmissions are conducted under the guidance of scientists and engineers using a powerful planetary radar. The scientific messages included in the transmissions utilize sophisticated encoding techniques based upon basic mathematics and scientific concepts.

There are many analogues in the natural and social sciences to METI. Consider a medical researcher who injects a particular substance into laboratory mice to see how their biological systems react. Or consider an economist, a social scientist, who examines how a new government regulation affects a market system. Or consider an ecologist who studies how the introduction of a pollutant into the environment affects the living system in which we all exist. Similarly, we tweak a system, the ETI community in the Milky Way Galaxy, with METI transmissions in the hope that an ETI will respond, thus answering one of the most fundamental questions of science: Are we alone?

But METI is not just a science, it is also an art. Earth's science is the product of the human mind, which in turn is affected by the cultural and historical influences - and accidents - of human history. The way an ETI views nature may not conform to our scientific paradigm. So, to increase the likelihood of effective communication across interstellar space, we include in our METI transmissions non-scientific messages: text, audio, video, art, music, etc. For example, Teen Age Message 2001 included the Theremin Concert for Aliens, possibly the first analog interstellar radio message.

2. METI is risky

Is it possible that the ETI whom we contact is an evil, imperialistic sort that, upon receiving our messages, will fly to Earth and gobble us up? We call this the Darth Vader Scenario.

Setting aside the plausibility of physical interstellar travel, and whether it would be worth it to Mr. Vader to travel to our neck of the galactic woods, we should recognize that avoiding a risk is itself risky. Another equally plausible scenario is that the ETI we contact is a Luke Skywalker who responds to our METI message both by warning us of Lord Vader's sinister nature, and by telling us what steps we can take to defend ourselves. Assuming Darth is imperialistic and is exploring the various star systems of the galaxy, he may eventually find us anyway. Wouldn't we be better off with Luke's sage advice?

And what of the risk of not learning what we can from an ETI? Perhaps the knowledge and wisdom an ETI could impart to us would save us from humanity's self-destructive tendencies, such as nuclear war, biological warfare, or environmental degradation.

The tendency to focus on the dangers of exploration is nothing new in human history. Centuries ago, everyone knew that mariners who sailed too far over the oceans would fall off the edge of the Earth, or be eaten by sea monsters. Yet humans dared to explore. They took the risk of encountering the presumed sea monsters - their own version of Darth Vader - and discovered a new world inhabited by an alien civilization with alien crops and resources.

3. METI is pointless

This argument holds that CETI, the two-way communication process of which METI is a part, is too time-consuming. For example, a Cosmic Call transmission aimed at a star 100 light-years from Earth will take a century to reach its target star. Assuming ET replies, another century will elapse before we receive the reply. 200 years far surpasses the lifetime of any of us alive today.

History is full of examples of people who undertook great projects to benefit future generations. For example, it often took several generations of workers to build the great cathedrals of Europe. And in our everyday lives, parents and grandparents make tremendous sacrifices to ensure their offspring are educated and prepared to lead happy lives far after the parents and grandparents have passed away.

As Carl Sagan once put it, "For those who have done something they consider worthwhile, communication to the future is an almost irresistible temptation, and it has been attempted in virtually every human culture. In the best of cases, it is an optimistic and far-seeing act; it expresses great hope about the future; it time-binds the human community; it gives us a perspective on the significance of our own actions at this moment in the long historical journey of our species."

In conclusion, we subscribe to one possible solution to the Fermi Paradox: Suppose each extraterrestrial civilization in the Milky Way has been frightened by its own SETI leaders into believing that sending messages to other stars is just too risky. Then it is possible we live in a galaxy where everyone is listening and no one is speaking. In order to learn of each others' existence - and science - someone has to make the first move.

Disclaimer: The opinions expressed in editorials are those of the individual authors, and do not necessarily reflect the position of The SETI League, Inc., its Trustees, officers, Advisory Board, members, donors, or commercial sponsors.

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