Earthshine for Moon - how to track for long exposure?

I've been looking up how to do Earthshine and a lot of the tutorials have exposure times in the seconds range in order to capture the Earthshine in the darker regions of the moon -- often without a tracker. However, I'm not understanding how this can be done without significant motion blur since the moon travels quite fast across the night sky... so I came to the conclusion that they must be using a tracker of some sort.

Having said that, I'm looking for solutions on how to track the moon. I'm assuming that I can make a barndoor tracker of some sort for this purpose. Once I align to Polaris, how do I calculate the speed at which the moon rises so I can align my tracker?