To find ET, look at who’s (maybe) looking at us
![map of stars in Milky Way that could see Earth in front of sun](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2016/04/043016_scivis_feat_free.png?fit=860%2C460&ssl=1)
EXTRATERRESTRIAL SURVEILLANCE Eighty-two known stars (blue dots) within 3,500 light-years of Earth could host advanced civilizations that can see Earth cross in front of the sun.
E. Otwell, C. Crockett; Source: R. Heller and R.E. Pudritz/Astrobiology 2016