File:Uncertain size-frequency distribution of interstellar visitors.jpg

English: Interstellar visitors in the Solar System cover the whole range of sizes - from kilometer large objects down to submicron particles. Also, interstellar dust and meteoroids carry with them valuable information from their parent systems. Detection of these objects along the continuum of sizes is, however, not evident [Figure, Reference: Hajdukova et al., 2020, PSS 192, 105060].

The smallest interstellar dust particles are filtered out of the solar system by electromagnetic forces, while the largest ones are too sparse to obtain good statistics from in situ spacecraft detectors. Discrimination between interstellar and interplanetary populations can be a challenge for intermediate (0.1-1 micrometer) sizes. These can vary widely in velocity and directionality (Sterken et al., 2012). The identification of interstellar meteoroids, observed in the Earth’s atmosphere as meteors, is highly challenging and requires high accuracy measurements and appropriate error examinations [Hajdukova and Kornos, 2020, PSS 190, 104965]. Otherwise, measurement errors can transfer near-parabolic orbits over the parabolic limit and create an artificial population of hyperbolic particles, often interpreted as of interstellar origin [Hajdukova Hajdukova et al., 2020, PSS 192, 105060].

Large interstellar visitors like asteroids and comets were detected the first time in the solar system in 2017 (1I/'Oumuamua) and 2019 (2I/Borisov) and are expected to be detected more frequently with new telescopes, e.g. the Vera Rubin Observatory.