The search for extraterrestrial intelligence usually targets narrow radio beams. But Earth's technosphere increasingly fills the ether with broadband noise. Similarly, alien civilizations might reveal themselves not by beacons, but by a continuous radio hum. This approach will extend the search zone to 100 parsecs.
🎯 If a narrow radio beacon is a lone whistle in the night, then a planet's technogenic hum resembles the cacophony of a big city: a mix of conversations, engines, and music across all frequencies.
🎬 In Carl Sagan's novel "Contact," aliens sent a complex narrow signal. The new approach suggests we're more likely to pick up the unintended noise of their technology—the same kind our own internet traffic generates.