  In 2016, a star KIC 8462852 caught the world's attention due to a paper by
citizen scientists who noticed its seemingly unexplainable 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. 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. 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. 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. 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.
