A team of scientists from the Planetary Habitability Laboratory (PHL) at the University of Puerto Rico at Arecibo believe they may have finally solved the 47-year-old mystery of the infamous “Wow! Signal.”

Detected by the Ohio State University Big Ear Telescope on August 15th, 1977, the Wow! Signal got its name because astronomer Jerry R. Ehman was so impressed he wrote “WOW” in the signal printout’s margins. Since then, the signal has continued to fascinate the scientific community, including the possibility that it may have been sent by an extraterrestrial civilization light years from Earth due to its high power, strong signal-to-noise ratio, and narrow bandwidth.

Unfortunately, various efforts to detect a repeat of the signal, which had a frequency and duration that didn’t match any known natural phenomenon, have come up empty, leaving the exact nature and origin of the potentially artificial signal unsolved. Several efforts in the ensuing decades have tried to offer potentially natural explanations for the signal. However, those attempts have also come up short of providing a definitive solution, leaving scientists to wonder if the Wow! Signal was indeed of extraterrestrial origin.