EmbedVideo(5417, 482, 304); Here's a little-known winter fact: Ski moguls, those tricky-to-navigate bumps on well-traveled ski runs, migrate slowly uphill. Moguls are formed by skiers on virtually all ski trails that are not mechanically flattened with grooming…

Science correspondent Miles O'Brien plunged into a muck of that which rhymes with "it" to investigate our ailing sewage system. Here's his story of what happened underground. Don't miss his full report on tonight's NewsHour.

Photo by Susan Smith via Flickr. Humans may have developed our long life spans as a result of nature's first babysitters: grandmothers. A new study published in the Proceedings of Royal Society B on Wednesday uses a…