SETI’s 100-Million-Channel Scan for Extraterrestrial Signal Put on Hold — Where Does the Search Go From Here?


Funding for the SETI Institute has dried up, meaning the search for extraterrestrial intelligence lost one of its key drivers on the planet. In an letter dated April 22nd, reports the San Jose Mercury News, SETI Institute's CEO, Tom Pierson, reported that the array had to be put into "hibernation." The equipment will be maintained, but won't be able to operate — the government funding simply isn't there. So the technology that was developed for the SETI antenna arrays that monitor 100 million channels simultaneously will no longer be transmitting that long search for signals from another advanced civilization in the Milky Way.

SETI’s mission to find life on other planets is like trying to find the proverbial needle in a haystack. But now, whenever Kepler identifies planets most likely to sustain life, the team at SETI will no longer be able to focus in on those solar systems using deep-space listening equipment.

The technology being put on hold is called the Allen Telescope Array, known formerly as the One Hectare Telescope, or 1hT, is a joint effort by the SETI Institute and the University of California, Berkeley located in the High Sierras just north of Lassen Peak. Because of its novel construction — an array of inexpensive antennas — it can be simultaneously used for both SETI and cutting-edge radio astronomy research.

Because of its ability to study many areas on the sky at once, with more channels and for 24 hours a day, the Allen Telescope Array allowed an expansion from Project Phoenix's stellar reconnaissance of 1,000 stars to 100 thousand or even 1 million nearby stars. For the first time in its forty-year history, SETI was able to check out a truly significant sample of the cosmic haystack.

The conceptual foundation for most of the SETI projects conducted in the past 35 years was established with the publication of a paper authored by the founding fathers of SETI, Manhattan project leader and MIT physicists Phillip Morrison and Guiseppi Cocconi, and the suggestion that electromagnetic signals were the most promising means for interstellar communications became the underlying assumption of all searches, including the optical SETI searches.

The presence of an extraterrestrial signal from another intelligent civilization, Morrison and Cocconi argued, is consistent with all that is known about physics, communication via electromagnetic waves, and communication. "The probability of success is difficult to estimate," they concluded, "but if we never search, the probability of success is zero."

The assumption that any alien signal would exhibit a Doppler drift was also incorporated into SETI projects, which checked for signals at drifting frequencies. Perhaps most important was their theory that a "universal frequency" probably exists — a frequency that extraterrestrials would most likely use for their transmissions — which they suggested to be 1420 megahertz. Notably, that frequency has remained, to this day, the most popular frequency used by SETI projects.

That's a sad loss because the recent discovery of Earth-like planets outside our solar system, which has led astrophysicists to conclude that Earth-like planets are likely relatively common in our galaxy.

"Everything has caused us to become more optimistic," said American astrophysicist Dr Frank Drake in a recent BBC documentary. "We really believe that in the next 20 years or so, we are going to learn a great deal more about life beyond Earth and very likely we will have detected that life and perhaps even intelligent life elsewhere in the galaxy."

However, some astrophysicists have warned that we humans may be blinded by our familiarity with carbon and Earthlike conditions. In other words, what we’re looking for may not even lie in our version of a “sweet spot”. After all, even here on Earth, one species “sweet spot” is another’s species worst nightmare. In any case, it is not beyond the realm of feasibility that our first encounter with extraterrestrial life will not be a solely carbon-based occasion.

Alternative biochemists speculate that there are several atoms and solvents that could potentially spawn life. Because carbon has worked for the conditions on Earth, we speculate that the same must be true throughout the universe. In reality, there are many elements that could potentially do the trick. Even counter-intuitive elements such as arsenic may be capable of supporting life under the right conditions. Even on Earth some marine algae incorporate arsenic into complex organic molecules such as arsenosugars and arsenobetaines. Several other small life forms use arsenic to generate energy and facilitate growth. Chlorine and sulfur are also possible elemental replacements for carbon. Sulfur is capably of forming long-chain molecules like carbon. Some terrestrial bacteria have already been discovered to survive on sulfur rather than oxygen, by reducing sulfur to hydrogen sulfide.

Nitrogen and phosphorus could also potentially form biochemical molecules. Phosphorus is similar to carbon in that it can form long chain molecules on its own, which would conceivably allow for formation of complex macromolecules. When combined with nitrogen, it can create quite a wide range of molecules, including rings.

So what about water?  Isn’t at least water essential to life?  Not necessarily. Ammonia, for example, has many of the same properties as water. An ammonia or ammonia-water mixture stays liquid at much colder temperatures than plain water. Such biochemistries may exist outside the conventional water-based "habitability zone". One example of such a location would be right here in our own solar system on Saturn's largest moon Titan.

Hydrogen fluoride methanol, hydrogen sulfide, hydrogen chloride, and formamide have all been suggested as suitable solvents that could theoretically support alternative biochemistry. All of these “water replacements” have pros and cons when considered in our terrestrial environment. What needs to be considered is that with a radically different environment, comes radically different reactions. Water and carbon might be the very last things capable of supporting life in some extreme planetary conditions.

At any rate, the odds of there being some type of life somewhere out there are good. As for intelligent life, well, that will depend on the definition of intelligence. There are a lot of other intelligent species here on Earth, besides humans, that we don’t generally regard as such. In spite of many Star Trek episodes to the contrary, the odds of alien life forms having evolved to talk, look and act exactly like super hot humans are slim to none.

If life is out there, it will have evolved according to its particular niche in the universe and will likely be quite foreign to us in the way it looks, communicates and thinks. We might not even be able to recognize hypothetical life forms as alive in the sense that we understand life. In fact, it would be more “miraculous” if we could effectively communicate with extraterrestrial life than to find that it exists.

The Daily Galaxy via Reuters and SETI Institute

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