On August 15, 1977, a radio telescope in Ohio detected a powerful, narrowband radio signal lasting 72 seconds. It was so striking that astronomer Jerry Ehman circled it and wrote “Wow!”—hence the name. The signal came from the direction of the Sagittarius constellation and matched what scientists imagined an alien transmission might look like. Despite many attempts, it’s never been heard again. No natural or human-made source has been definitively linked to it. To this day, the Wow! Signal remai

The Science of Radio Astronomy - National Radio Astronomy Observatory

Historic Puerto Rico radio telescope, already damaged, collapses