I browsed a lot this forum to find an answer, but it always ends up in the same way : no constant answer. I understand how time dilation relative to speed or to gravity separately work. But what about an object orbiting at high speed (natural ans stable orbit) an other object with a significant mass? How would those two effect would interact? How would you calculate the effect of time dilation, of an object moving in a gravity field, knowing the mass of the central object and the orbit radius? I have seen a lot of different answers, some pull out equations combining both gravity and relative speed time dilation laws and other say there is no connection but without giving any answer or explaining why, some other say it is the same, but again without answering thr question. Can anyone help me?