Earth through the looking glass: how frequently are we detected by other civilizations through photometric microlensing?

ABSTRACT Microlensing is proving to be one of the best techniques detect distant, low-mass planets around most common stars in Galaxy. In principle, Earth’s microlensing signal could offer chance for other technological civilizations find Earth across Galactic distances. We consider photometric potential and dub regions our Galaxy from which readily observable as ‘Earth zone’ (EMZ). The EMZ can thought analogue Transit Zone (ETZ) where observers see transit Sun. Just ETZ, represent a game-theoretic Schelling point targeted searches extra-terrestrial intelligence (SETI). To compute EMZ, we use Gaia DR2 catalogue with magnitude G < 20 generate probability detection rate maps observers. While Solar system multiplanet system, show that signature almost always well approximated by binary lens assumption. then fact hidden technology comparable own. Specifically, even if are located every star 20, expect signatures on average only tens per year any them. addition, EMZs overlap ETZ near Centres main areas future SETI searches.