Interstellar Visitors

William sent in a link to a video – see https://www.msn.com/en-us/news/technology/a-137-000-mph-intruder-entered-the-solar-system-at-the-wrong-angle/vi-AA24y7DT … one to chew on. A 137,000 mph intruder entered the solar system at the wrong angle, we are told. The solar system looks flat because the planets, asteroids, and most local objects all move around the Sun in the same broad plane. That makes it hard for spacecraft to escape up or down. Rockets must  fight the sideways orbital speed inherited from Earth. Yet, interstellar visitors, such as Oumuamua, Borisov, and 31/ATLAS can enter from steep angles because they were never part of that orbital plane. The most unsettling detail is that estimates suggest there are thousands of interstellar objects passing inside Neptune’s orbit. Surveys mostly watch the planetary plane and may miss what drops in from above or  below. This seems to put a different slant on what might have occurred in the past. Asteroids and comets with a solar system origin may not threaten life on Earth apart from the odd occasion – but how can we  calculate how often a dangerous object from interstellar space may pass through the solar system, some of which would come close to the Earth.