9. Unusual Patterns in Cosmic Background Radiation
Scientists examine the cosmic microwave background—the afterglow of the Big Bang—for any odd fluctuations or patterns. These anomalies might indicate large-scale engineering or communication efforts by advanced civilizations. Even subtle shifts, if unexplained by natural processes, could be a sign of extraterrestrial activity (ESA). It’s yet another way researchers keep their eyes open for cosmic footprints.