Solar tsunamis are real, says NASA

Incredibly powerful waves of plasma rippling across the surface of the sun and dubbed "solar tsunamis" were first observed years ago, but were thought to be an optical illusion. Scientists have now confirmed, though, that they are really real.When scientists first saw the phenomenon, it was hard to believe that a towering wave of hot plasma was actually racing along the sun's surface.One of the waves rose up higher than the diameter of Earth and rippled out from a central point in a circular pattern millions of miles wide, like a gargantuan pattern of waves created by a pebble dropped in a pond.Skeptical observers suggested it might be a shadow of some kind – a trick of the eye. But new observations from NASA's STEREO (Solar Terrestrial Relations Observatory) spacecraft are telling researchers that this controversial phenomenon isn't an illusion.