When Voyager 1 thundered away from Cape Canaveral on Sept. 5, 1977, its primary mission was to explore the solar system, but the extras were what engaged the public imagination. In a utopian anticipation of its discovery by extraterrestrial intelligence somewhere Out There, the NASA probe — and its Voyager 2 twin — was fitted with a gold-plated disc featuring samples of 115 languages, music, photos and the natural sounds of life on Earth.

Both spacecraft flashed past Pluto way back in 1990, and scientists are debating whether or not the vehicles have actually departed our solar system. Either way, nearly 36 years later, at more than 18 billion kilometers from Earth, Voyager 1 is the farthest flung hardware our species has ever created.

“As technology advances in complexity and scope, fear becomes more primitive.” ― Don DeLillo/CREDIT: swissnexsanfrancisco.org

Three years after the Voyagers left home, nanotechnologist Robert Freitas leaped many generations ahead and co-authored a NASA feasibility study on self-replicating probes (SRPs). He contemplated what it would take for advanced space-faring technology not only to repair and perpetuate itself during missions, but also to improvise on destination targeting as it forged the cosmic oceans. Among the motivations for this exercise was a theoretical test of the Fermi Paradox, in which physicist Enrico Fermi alleged, in 1950, that if ET civilizations existed, we would’ve known it by now. “Where are they?” he wondered.

In 1983, Freitas confronted the Paradox in the International Journal of the British Interplanetary Society by suggesting that ET probes — not quite as naive as our little Voyagers — might be more discerning before initiating contact. He hypothesized that ET engineers would be too smart to dispatch scout vessels capable of breaking down into derelict shells subject to recovery by inferior societies. Freitas envisioned a scenario in which these auto-repair SRPs might also camouflage their presence and maintain communications blackouts until the “recipient species” could pass a “threshold test” for native intelligence or technological prowess. He suggested SRPs could be exploring our neighborhood even as we speak.

This provocative notion was challenged in the July edition of The International Journal of Astrobiology by Scottish mathematicians Arwen Nicholson and Duncan H. Forgan at the University of Edinburgh. Nicholson and Forgan proposed that, without goring the sacred cow of light speed, ET engineers from older civilizations could design Voyager-sized SRPs and, using stars for gravitational velocity assists, “slingshot” them across the void up to 100 times faster than the Voyagers.

It’s a far-out idea, literally and figuratively. The authors assume that these SRPs, approaching no closer than 10 percent the speed of light, could produce, in transit, multiple, time-saving duplications of themselves, which could then be dispatched to plow, in coordinated fashion, distant corners of the Milky Way Galaxy for signs of intelligent life. Bottom line: SRP fleets using the Nicholson-Forgan algorithms could have surveyed our star system in the relatively short span of 10 million years — plenty of time to have discovered Earth. Lacking evidence of such surveillance, the authors conclude “the question underlying the Fermi Paradox is well posed.”

Given how these SRPs build upon the “post-biological” robotic ET probes proposed in the International Journal of Astrobiology by former NASA historian Steven Dick in 2003, De Void felt compelled to reach out to Dr. Dick about the latest theoretical scenario.

“This is a serious argument against ETI. Since we don’t see them here, they don’t exist,” he surmised in an email. “Maybe there is no interstellar travel because it’s too expensive, physically impossible, too hazardous, or ETI’s aren’t interested. Or they are here but undetected. Or they just don’t exist. Given these possibilities, most astronomers continue to argue we will only know for sure by looking for them with radio searches, etc. UFO reports are another matter …

“There are indeed a very few percent of UFO reports that remain unexplained. But as (Carl) Sagan always said, ‘extraordinary claims require extraordinary evidence,’ and extraordinary evidence is not available (or you would have heard of it!). I conclude there may be something unexplained going on with those few percent, whether something physical, psychological, or sociological, but to jump to the ‘extraterrestrial hypothesis’ is unwarranted at this time.”

During our exchange three years ago, Dick informed De Void he had not reviewed MUFON’s radar analysis of the 2008 Stephenville Incident, nor had he read Leslie Kean’s UFOs: Generals, Pilots and Government Officials Go On the Record, which earned the endorsements of blue-chip astronomers Michio Kaku and Derrick Pitts. Significantly, both declined to paste an extraterrestrial label on the phenomenon; they simply advocated serious UFO research.

Might the furtive and transient nature of most UFO encounters — combined with the stealth/cloaking behaviors reported in so many instances — be a manifestation of Freitas’ hypothesized SRP “threshold tests” for gauging intelligence? Why not subject the data to our own rigorous tests? De Void posed the question to Dick in a followup, and also asked if he was familiar with any of the compelling studies published by his former NASA colleague, Richard Haines, at the National Aviation Reporting Center on Anomalous Phenomena.

This time, Dick didn’t bother to answer.