A Drake Equation for Alien Artifacts

“I propose a version of the Drake Equation for Lurkers on near-Earth objects. By using it, one can compare a Search for Extraterrestrial Artifacts (SETA) strategy of exploring for artifacts to the conventional listening-to-stars SETI strategy, which has thus far found no artificial signals of technological origin. In contrast, SETA offers a new perspective, a new opportunity: discovering past and present visits to the near-Earth vicinity by ET space probes.”

—Paul Gilster, “A Drake Equation for Alien Artifacts.” Centauri-Dreams.org. April 20, 2021.

Imagine an alien civilization finding the Voyager space probes a billion years in the future. Over the span of cosmic time, how many other civilizations managed the same? What is the typical civilizational life span of those civilizations capable of doing it?

Then, there is the question of how many would have survived and developed far enough to place probes in nearby stars with environments conducive to life?

From the Edge of the Universe to the Inside of a Proton

“But we should count ourselves lucky; there have not always been 62 orders of magnitude of universe to explore, and there won’t always be. As Scharf explained, ‘If you turn the clock back far enough to the Big Bang, obviously there was a time when the number of scales that were causally connected were fewer, and space itself was smaller.’ Likewise, ‘if you extrapolate 100 billion years into the future, assuming the current accelerating expansion, it will be essentially impossible for us to see anything much beyond our galaxy or our local group of galaxies.’ Scharf said this seems to mean we’re living at a special time. And he wondered, ‘Would someone in the future be able to figure out how the universe works?’”

—Natalie Wolchover, “A Tour of the Zoomable Universe by Caleb Scharf and Ron Miller.” Quanta Magozine. November 6, 2017

The inspiration for this coffee table book was to update the information in a famous short film, The Powers of Ten (1977):