If you want to evenly space them, it's easiest to alternate between the Arctic and Antarctic. Some people just go to the Arctic twice, near the equinoxes so the visits are almost 6 months apart, but it's not the same.
Special 10th anniversary edition of WHAT IF?—revised and annotated with brand-new illustrations and answers to important questions you never thought to ask—coming from November 2024. Preorder here!
