In the early hours of April 13, 2029, a 340-metre asteroid named for the Egyptian god of chaos will pass closer to Earth than our own weather satellites — and do so in full view of most of humanity. Apophis, once briefly feared as a genuine threat, was cleared of all impact risk through the patient accumulation of better measurements, a reminder that knowledge itself is a form of protection. What remains is something rarer than danger: a celestial event visible to billions, a natural experiment in planetary physics, and a quiet rehearsal for the long, careful work of understanding the sky befo