The Tail That Faces the Wrong Way

You spotted it weeks before anyone else in your village. A smear of cold light in the eastern sky, like a candle flame someone forgot to blow out. But the flame faces the wrong way. The comet is moving east — you can tell, night by night — and yet its tail streams west, back along the path it came from, billowing away from the sun like smoke in a headwind. That is exactly what it is. There is no fire behind a comet. There is no burning. The sun itself is blowing it apart. A constant invisible gale pours out of the sun in every direction — a river of charged particles moving so fast it takes only days to cross the gap between the sun and Earth. We call it the solar wind, and it is always, always blowing, right now, against your face, through your walls, through you. A comet's tail is just the first thing flimsy enough to show you the shape of that invisible river. The comet arrives from the outer dark as a frozen lump the size of a city — ice and rock and ancient dust packed together since before the Earth existed — and the sun's breath strips it open like a flower. That is the light you are watching. Destruction, travelling backwards. And a comet's tail can stretch for a hundred million kilometres, longer than the distance between the Earth and the sun, pointing always, precisely, directly away from the star trying to erase it.