In 2015, a star KIC 8462852 caught the world’s attention due to a paper by citizen scientists who noticed its seemingly unex-plainable brightness variations. The forward theory was offered – KIC 8462852 is surrounded by a Dyson sphere, a megastructure made by an alien civilization to collect all energy output from their star. This put the world into observational frenzy centred on the star and, finally, in 2018, its light curve showed chromaticity more characteristic of the dust (from comets or asteroids) rather than of something made from solid material, but the world was woken up to the idea of megastructures. Freeman Dyson suggested in 1960 that extraterrestrial intelligence (ETI) might build a megastructure around the star to collect all energy output, since the increase in the global material usage, energy consumption and population will eventually lead us to look for more resources, energy sources and living space. But in Dyson’s time, only Solar System planets were known; it took more than 20 years to realize that nature has no problem making planets and does it with a flair – the total number of planets in the Galaxy is estimated to be in billions. With such abundance of planets, there would be no need to destroy the entire planetary system to make one sphere. Besides, to construct just an 8–20-cm thick shell would require all Solar System’s rocky material including Earth, destroying any possible life, which goes against the principle of Planetary Protection – the UN policies governing the preservation of Solar System bodies. Instead, a civilization can expand to a system that has planet(s) in the habitable zone (HZ), or a planet can be moved into it. Alternatively, a free-floating planet (FFP) can be captured and moved into the HZ. These shifts can be performed at a constant low-thrust acceleration using high power directional lasers, resulting in a gradual spiral transfer from one orbit to another. Different types of planets could be captured and moved into the system depending upon the needs. We propose here to search for ETI by looking for high-power laser technosignatures and consider merits of such signatures. We suggest to specifically pay attention to the multiple planetary systems that have Strange Exoplanetary Architectures (SEA) – unusual planetary arrangements that cannot be explained by current planetary formation theories, because these could be the result of ETI moving planets intentionally to suit their needs.
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