🛰️ Asteroid Impact Probability Lab: Orbit Uncertainty, the B-Plane and Why Odds Collapse

Shows how an asteroid's impact probability is the integral of a 2-D Gaussian uncertainty ellipse in the B-plane over the gravitationally focused Earth disc, and why it first rises then collapses as observations accumulate. Unlike the existing deflection and impact-effects sims, it focuses on risk assessment (Torino/Palermo scales, keyholes, Monte-Carlo virtual impactors).