NASA / NASA via Getty Images We may be able to find evidence of advanced alien civilizations in pulverized traces of their technology. Oxford astrophysicist Brian Lacki argues in a new, yet-to-be-peer-reviewed paper that, instead of searching for radio signals from space to find aliens, which would require active maintenance, we should look for “passive” signs of their technology that endure without upkeep, as the possibility of aliens existing at the same time as us is low. Dr. Lacki identifies