How long does it take for planets to replenish?

As you mine/probe planets for resources, the returns you get diminish, but I've noticed that upon revisiting a system after a few turns the planets are "full" again. How long does it take for a planet to refill?

I'd really like to know this too. Has anyone figured it out? I have to go in circles to relearn telescope tech (again!) in order to avoid scumming the save system to do it.

Bifford wrote:As you mine/probe planets for resources, the returns you get diminish, but I've noticed that upon revisiting a system after a few turns the planets are "full" again.  How long does it take for a planet to refill?

They replenish immediately after you leave the system.

So if you find a planet with a ton of resources you need e.g. iron or fuel, just come right back and stock up again.