On the 12th of August, the Moon will interpose itself between Earth and Sun, briefly erasing daylight from a narrow corridor stretching across northern Spain, Portugal, Iceland, and beyond — the first such total eclipse visible from mainland Europe in 127 years. For those outside the path of totality, including most of Britain and Ireland, the sky will still dim and distort in ways that remind us how rarely we notice the light we live inside. Celestial mechanics are indifferent to borders, but this particular alignment arrives close enough to populated land that millions may choose, for once,