The Size Distribution of Interstellar Objects and the Mass It Places in Transit

This paper addresses a single quantitative question about interstellar objects and interstellar traversal: If the counts of interstellar objects follow a power law in diameter, how much mass is in transit and which sizes dominate it? Working from published survey values for the known interstellar objects and for the local interstellar medium, the paper computes cumulative counts at several slopes and the integrated mass density. The headline values obtained are N1_q35 = 3.16e-04; N10_q35 = 1.00e-06; M = 2.54e+09. 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.