Abstract
The ultimate technosignature is an alien artifact. We should look for
them near Earth. The great virtue of searching for artifacts is their
lingering endurance in space, long after they go dead. I compare a
Search for Extraterrestrial Artifacts (SETA) strategy of exploring near
Earth for alien artifacts to the existing listening-to-stars SETI
strategy. Stars come very close to Earth frequently. About two stars per
million years come within a light year. An extraterrestrial civilization
that passes nearby can see there’s an ecosystem here, due to the
out-of-equilibrium atmosphere. They could send interstellar probes to
investigate. The Moon and the Earth Trojans have the greatest
probability of a successful search by us, ET archeology. I suggest
resources devoted to imaging of our Moon’s surface, the Earth Trojans
and Earth co-orbitals, and for probe missions to the latter two. The
SETA concept can be falsified: if we investigate these near-Earth
objects and don’t find artifacts, the concept is disproven for this
region. Close inspection of bodies in these regions, which may hold
primordial remnants of our early solar system, yields concrete
astronomical research.