With the discovery of two interstellar objects, astronomers have learned that material is freely drifting around the Milky Way. So what about the closest star system, Alpha Centauri? According to a new paper, asteroids and comets are constantly escaping the grasp of the stars in the system and making the journey to the Solar System. The journey takes about 10 million years, and they estimate there could be about 1 million large particles from Alpha Centauri already here.