(TMU) — Provided humanity doesn’t destroy itself, someday our technology may advance to the point where we can send probes to other star systems to look for tell-tale signs of life on exoplanets.
A new idea in physics, however, inverses this hypothetical to suggest that perhaps we, or our ancient ancestors, may have been (or still are) under a kind of surveillance by an alien civilization that uses robotic probes to keep tabs on the development of life on Earth.
While it may sound like a story right out of a science fiction novel, many physicists say it is completely possible that an advanced alien species would use co-orbitals—relatively nearby space objects that share a similar orbit around the sun—to study our planet and the life that has flourished on it for billions of years.
A new paper and many Search for Extraterrestrial Intelligence (SETI) researchers promote the idea that these alien spy probes may have left an “archeological record” sometime in our distant past—and that we may be able to find the alien technology embedded in co-orbitals near the Earth.
In his recently published paper on the subject, “Looking for Lurkers: Co-orbiters as SETI Observables,” physicist James Benford discusses how co-orbital objects are relatively unknown and sometimes have strange shapes. The nearest, known as “Earth’s Closest Companion,” is 38 times the distance from Earth as the moon.
As stated in the paper’s abstract:
“A recently discovered group of nearby co-orbital objects is an attractive location for extraterrestrial intelligence (ETI) to locate a probe to observe Earth while not being easily seen. These near-Earth objects provide an ideal way to watch our world from a secure natural object. That provides resources an ETI might need: materials, a firm anchor, and concealment.”
In the future, co-orbitals may turn out to be the ideal hubs for studying the “technosignatures” of our neighboring exoplanets. SETI and NASA have never studied the co-orbitals closest to Earth in a focused way, nor have they sent any kind of probe to one.
“How likely is it that alien probe would be on one of these co-orbitals, obviously extremely unlikely,” remarked Paul Davies, a physicist and astrobiologist at Arizona State University who has written extensively about the possibility of ET. “But if it costs very little to go take a look, why not? Even if we don’t find E.T., we might find something of interest.”
While finding such a probe may be unlikely, other scientists consider it just as unlikely that in the past 4.5 billion years no alien species has searched the galaxy for signs of life. If they did, and are advanced enough to develop probes that can study planets—which, even in our technological infancy, we’re already doing—it seems likely they would be interested in a planet like the Earth that is so flush with life.
“If we don’t find anything, that means no one has come to look at the life of Earth for over billions of years,” said Benford. “That is a big surprise, a stunning thing.”