Dust Impact Energies During Relativistic Interstellar Flight

This paper addresses a single quantitative question about interstellar objects and interstellar traversal: How energetic is a single sub-micron dust grain struck at a tenth of light speed, and how many such grains meet a vehicle on the way to the nearest star? Working from published survey values for the known interstellar objects and for the local interstellar medium, the paper computes per-grain impact energies for two grain sizes at three speeds and the grain column to Proxima Centauri. The headline values obtained are E01_01c = 5.69e-03; E1_01c = 5.69e+00; col = 8.27e+08. Each number is produced by the deposited computation script from inputs that are stated in full, so the result can be reproduced, checked and updated as survey measurements improve. The study is a computation from stated assumptions and published data; it presents no new observations. Its contribution is a transparent budget: a set of numbers, the relations that produce them, and an explicit account of how sensitively each number depends on the assumptions behind it.