For noted theoretical physicist Frank Wilczek, finding aliens is a matter of figuring out what exactly we are looking for. To detect other space civilizations, we need to search for the specific effects they might be having on their worlds, argues the Nobel laureate in a new proposal.

Writing in the Wall Street Journal, Wilczek says that it’s a real challenge to figure out which among the over 4000 exoplanets that we found so far outside of our solar system might host extraterrestrial life. The classic way of listening for space signals is insufficient and inefficient, says the scientist. What might really help are new developments in exoplanetary astronomy that can allow us to get much more precise information about faraway space objects.

In particular, there are two ways we should focus our attention to turn the odds of finding alien life in our favor, argues the physicist.