Limitations on High-Speed Relativistic Interstellar Travel due to Interstellar Asteroidal and Cometary Material

Abstract

As technology improves, the possibilities for extended space travel do too. Traveling in our solar system over the next century will eventually transition to traveling around the Interstellar medium (ISM) hundreds of years from now. In the solar system, asteroids, comets, and other objects known as space debris can create a threat to satellites and spacecraft. This is especially true in the near-Earth environment due to the rapidly increasing numbers of artificial orbital satellites. The interstellar medium has the same danger but on a much different scale. Traveling between star systems poses a risk of hitting interstellar medium objects (ISO) while traveling at extremely high speeds that are necessary to reach the nearby stars within a person’s lifetime. Speeds such as 10-90% of the speed of light are thus necessary for interstellar travel. Traveling at high speeds in the interstellar medium is extremely dangerous. Impacting a pebble while moving at 50% of the speed of light will cause an explosion comparable to a small nuclear bomb. Thus, the question of the limits of interstellar travel becomes very important. The goals of this research are to determine the mean distance traveled in the ISM between collisions of various-sized objects, and the energy released in such collisions. Using the detection of the interstellar comet 'Oamuamua as a constraint on the abundance of interstellar material, we find that the density of smaller interstellar objects is much greater than initially predicted in the literature. This works provides updated constraints on the danger posed by relativistic interstellar travel.