The "Wow!" Signal

“”Wow” remains the strongest and clearest signal ever received from an unknown source in space, as well as the most fascinating and unexplainable. The signal’s original discoverer Jerry Ehman doesn’t care to speculate on its source, and he remains scientifically skeptical. “Even if it were intelligent beings sending a signal,” he said in an interview, “they’d do it far more than once. We should have seen it again when we looked for it 50 times.”
Perhaps. But consider that when humankind used the Arecibo radio telescope to send a message out into space in 1974, it was only sent once.”