it actualy has multiple things to consider gravity of objects that pull on it can influence the planet vilocity is another one vilocity is whats keeping us from just falling into the sun,orbital direction can also influence it,but the main things is gravity and vilocity if u dont have vilocity the object whold just fall in twords the biggest object and if you didnt have gravity every thing whold fly away an even things whold just fall apart.
