New modeling suggests Mercury acquired its polar water ice through a single, high-velocity impactor event lasting roughly one Mercurian day, rather than gradual cometary or asteroidal delivery. This reframes volatile acquisition as potentially stochastic and catastrophic, challenging the standard nebular and late-veneer paradigms that assume protracted accretion over millions of years. The New Scientist report draws on dynamical simulations but omits key details on methodology: the underlying study relies on N-body integrations with simplified volatile retention physics, without reported sample sizes for parameter sweeps or explicit Monte Carlo uncertainty quantification. Limitations include neglect of solar wind sputtering and micrometeorite gardening effects that could erode ice over gigayear timescales. Related peer-reviewed work from the MESSENGER mission (e.g., Neumann et al. 2013 in Science) mapped the ice deposits but could not constrain delivery timing; a 2022 Icarus paper on C-type asteroid delivery to terrestrial planets similarly assumes multi-impact scenarios without testing single-event extremes. Synthesis of these sources reveals the missed implication: if Mercury's water arrived in one day, analogous pulses may explain Earth's water heterogeneity and the Moon's volatile depletion, pointing to early solar system dynamical instability as the dominant driver rather than steady-state migration. This single-day mechanism also predicts observable isotopic signatures testable by future missions like BepiColombo.