Is it possible that a satellite rotates planet infinitely without air resistance?

I am ignorant of physics besides college, and I would like to know if it is possible that a moon rotates its mother planet for an infinite time assuming there is no resistance of any form.

I came up with this question since once a moon starts rotating, it keeps rotating according to law of gravity. Isolate the system to the planet and its satellite. If I recall correctly however, second law of thermodynamics says that entropy is always non-decreasing and it is impossible to create an eternal machine. I was thinking about drawing an equivalence between eternal motion of the planet and an eternal motion of a machine, but this is clearly a contradiction; hence, this eternal motion of the planet cannot viewed as an eternal machine.

So what’s the difference? What makes the planet to be moving forever given that the initial speed is not 0? I forgot everything in physics, but I am fortunately quite familiar with elementary math, so any mathematical explanation suffices. Thank you very much in advance.