In February 2020, a group of SETI (Search for Extraterrestrial Intelligence) experts gathered for a brain trust to discuss the strategy for finding ETI artifacts and the implications of our own technosignatures. The discussions centered on both passive and active observations, including the use of optical and radio listening, radar imaging, and launching probes.
One key strategy for finding ETI artifacts is through passive observation, which involves listening for radio signals or other forms of electromagnetic radiation that extraterrestrial civilizations may emit. We can do this through the use of radio telescopes, such as the Allen Telescope Array in California, which is specifically designed for SETI research.
Another strategy is active observation, which involves sending out probes or other forms of communication to contact extraterrestrial civilizations. This could include sending out radio signals or launching probes to other planets or moons in our solar system, hoping to find evidence of past or present extraterrestrial life.
Radar imaging is also a useful tool for the search for ETI artifacts. By using radar to scan the surfaces of planets and moons, scientists can search for signs of artificial structures or other evidence of intelligent life.
The implications of our own technosignatures, or the evidence of our own civilization that may be detectable by other intelligent life forms, were also discussed at the brain trust. Some experts argue that broadcasting our existence to the cosmos could be dangerous, while others believe it is important to make ourselves known, hoping to contact other civilizations.
Despite these efforts, the possibility remains that we may find nothing. This could suggest that no ET intelligence has yet come to look at Earth, or that other civilizations are simply not as curious as we are, are good at concealing their activities, or have been lost to deep time. However, the search for ETI artifacts and the quest to understand our place in the universe continues to be an important area of research and exploration.