(National Oceanic and Atmospheric Administration) During a recent expedition to the largely unexplored depths of the northern Mid-Atlantic Ridge, marine researchers stumbled upon something odd: tiny holes excavated in the sediment, all arranged in dozens of relatively straight lines. Holes on the sea floor wouldn't usually be too perplexing, but these were dotted in an incredibly neat and evenly spaced pattern. If not for the fact they're located roughly 2.5 kilometers (1.6 miles) below the surface of the Atlantic Ocean, in the middle of nowhere, they could have been engineered by human hands. Researchers on board the US National Oceanic...