2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/122814It is known that the discs are detected for some of the extra-solar planetary systems. It is also likely that there was a disc mixing with planets and small bodies while our Solar System was forming. From our recent results, we conclude that the discs play two roles: the gravity makes planetary systems more chaotic and the drag makes planetary systems more resonant.published in the proceedings of the 9th APRIM, IAUAstrophysicstext