Prograte motion: so if a moon's orbital period is faster then its primary's day, it will eventually impact its primary's surface. If this moon's orbital period is slower than its host planet, it will slowly move further away. Retrograte motion: What are the effects of retrograte motion with respect to tidal deceleration and acceleration?
I have a submoon orbiting its primary moon whose orbital period is 20 hours while its primary's orbital period is 50 hours. This will eventually cause my submoon to impact its primary in the future. What if it orbits in a retrograte motion? Would that prevent it from impacting its primary?
The primary moon orbits a gas giant. There is a submoon orbiting the primary moon. The primary moon has a Hill Sphere of 48,000 km. The submoon is about 20,000 km away, well within the stable region of the Hill Sphere. I want the submoon's orbit to be stable fo a long time.