A color scan of the original computer printout of the "Wow!" signal as detected by the Big Ear Radio Observatory in 1977.
Credit: Big Ear Radio Observatory and North American Astrophysical Observatory (NAAPO)
An astronomer thinks he's pinpointed the source of a mysterious radio signal from space: a passing comet that nobody knew about. But his colleagues said they're still skeptical of the explanation, noting that comets don't emit radio waves in the right way.
Antonio Paris, an astronomer at St. Petersburg College in Florida, recently published a paper in the Journal of the Washington Academy of Sciences saying the mysterious "Wow! signal," a truly bizarre radio signal detected almost 40 years ago, seems to match up with the location of a comet called 266P/Christensen that hadn't been cataloged at the time. (The comet was discovered more recently, in 2006. Originally, Paris' hypothesis was that a second comet might also be the culprit, one called P/2008 Y Gibbs.) Explanations for the Wow! signal have ranged from intermittent natural phenomena, to secret spy satellites, to, yes, aliens.
Others aren't so sure. "We do not believe the two-comets theory can explain the Wow! signal," Jerry Ehman, the astronomer who discovered the Wow! signal in 1977, told Live Science. [5 Times We Thought We Found Aliens]