On August 15, 1977, astronomer Jerry Ehman circled a sequence of six alphanumeric characters—6EQUJ5—on a dot-matrix printout from Ohio State’s Big Ear radio telescope. With a quick stroke of a red pen, he scribbled "Wow!" in the margin, christening the most tantalizing deep-space anomaly in modern astronomy. The signal was intensely concentrated, narrowband, and broadcast precisely at 1420 MHz—the universal hydrogen line long theorized as the ideal interstellar calling card. Lasting the full 72 seconds the telescope swept past its coordinates, the transmission evaporated into the celestial background, never conclusively replicated despite decades of search efforts. In today's era of automated data pipelines and machine learning classifiers, the Wow! Signal endures as a romantic analog cliffhanger, reminding us that humanity's greatest cosmic question mark was flagged not by an algorithm, but by human curiosity scrawled in ink.