Mathematicians from Edinburgh University have conducted a study demonstrating the possibility that an advanced extraterrestrial civilization could use self-replicating probes to study the galaxy. Their findings show that their theoretical alien probes could have already arrived.
The mathematicians, Duncan Forgan and Arwen Nicholson, had their paper on the analysis of how probes could travel through space published in the Journal of Astrobiology. They studied the possibility that alien races used the gravity of stars to “slingshot” the probes in order to gain speed. This is a technique we already use for probes, such as the Voyager.
The Voyager 1 space probe was launched in 1977 and is just reaching the edge of our solar system. However, Forgan and Nicholson believe that older civilizations could have launched similar probes that are already here. They also speculate that alien probes could use a method of self-replication. They might collect dust and gas to build new versions of themselves during their long trips.
The researchers say, “We can conclude that that a fleet of self-replicating probes can indeed explore the Galaxy in a sufficiently short time.. orders of magnitude less than the age of the Earth.”
The question is, if they are here, why haven’t we seen them? Referring to speculation on this topic from NASA space expert Robert Freitas in 1983, Forgan suggests that the probes may be designed to hide themselves. Forgan explained: “The probe camouflages itself so as to set up a threshold test of the technology or intelligence of the recipient species, where the test must be met before the species is allowed to communicate with the device.”