Fraction of impactors discovered at least X before impact for four diameter bins (10–20 m, 20–50 m, 50–140 m, and >140 m), shown for an Argus-like survey. The y-axis lower limit is clipped at 10⁻³ (0.1%) to avoid unnecessary blank space. Several size–time combinations fall at or below this level, indicating discovery fractions consistent with close to zero at the resolution of this plot.