Welcome to spring -- and darkness on the South Pole

While today's vernal equinox may not mean precisely 12 hours of daylight, it does mark one of the two days a year the sun rises from due east and sets at due west. At the equator, one can see the sun passing directly overhead. On the North Pole, the sun skims across the horizon, starting six months of daylight, while on South Pole, six months of darkness begin.