  Asteroids that could collide with the Earth are listed on the publicly
available Near-Earth object (NEO) hazard web sites maintained by the US and
European space agencies (NASA and ESA). The impact probability distribution of
69 potentially threatening NEOs from these lists that produce 261 dynamically
distinct impact instances, or Virtual Impactors (VIs), were calculated using
the Asteroid Risk Mitigation and Optimization Research (ARMOR) tool in
conjunction with OrbFit. ARMOR projected the impact probability of each VI onto
the surface of the Earth as a spatial probability distribution. The projection
considers orbit solution accuracy and the global impact probability. The method
of ARMOR is introduced and the tool is validated against two asteroid-Earth
collision cases with objects 2008 TC3 and 2014 AA. In the analysis, the natural
distribution of impact corridors is contrasted against the impact probability
distribution to evaluate the distributions conformity with the uniform impact
distribution assumption. The distribution of impact corridors is based on the
NEO population and orbital mechanics. The analysis shows that the distribution
of impact corridors matches the common assumption of uniform impact
distribution and the result extends the evidence base for the uniform
assumption from qualitative analysis of historic impact events into the future
in a quantitative way. This finding is confirmed in a parallel analysis of
impact points belonging to a synthetic population of 10006 VIs. Taking into
account the impact probabilities introduced significant variation into the
results and the impact probability distribution, consequently, deviates
markedly from uniformity. The concept of impact probabilities is a product of
the asteroid observation and orbit determination technique and, thus,
represents a man-made component that is largely disconnected from natural
processes.
