Scientists said on Wednesday that the largest solar flare in five years is speeding toward Earth—and is on track to smack into the planet on Thursday. The cloud of sun matter vomited forth by our nearest star will hit the planet at 4 million miles per hour early on Thursday, scientists said, and has the potential to disrupt electrical grids and navigational equipment. “It’s hitting us right in the nose,” said one scientist from the National Oceanic and Atmospheric Administration. This most stellar of sucker punches is just part of the natural order of things on the cosmic scale, the professional stargazers said. The Earth has actually been going through a period of slow solar activity in the last decade.