Forecasters say we’re in for a strong El Niño over the next few months. They base that prediction on computer models and some other high-tech wizardry. They might have come up with a similar result, though, by doing what some South American villagers have been doing for centuries: keep an eye on the Pleiades. The Pleiades is a family of a couple of thousand stars. The brightest form a tiny dipper shape. In mythology, the Pleiades represented the Seven Sisters. Yet most skywatchers see six stars, while a few see nine or more. The precise number can be an indication not only of the viewer’s eyesight, but of the sky conditions. In fact, the cluster’s visibility has helped villagers in the Andes Mountains of South America decide when to plant crops. They look at the Pleiades when it first appears in the dawn sky, around the June solstice. Good visibility generally means good rains, so villagers plant crops early. But poor visibility means poor rains, so planting starts later. The Pleiades
