The Wow! Signal has baffled astronomers and space investigators for decades. But the mystery appears to have finally been explained by Antonio Paris, who has shown that comets haloed by hydrogen are the cause.
These comets, known as 266P/Christensen and 335P/Gibbs, have clouds of hydrogen gas millions of kilometers in diameter surrounding them. The Wow! Signal was detected at 1420MHz, which is the radio frequency hydrogen naturally emits. Notably, the team has verified that the comets were within the vicinity at the time, and they report that the radio signals from 266/P Christensen matched those from the Wow! signal.