Entire lifetimes have come and gone without the moon looking quite as large as it will this month. On November 14th, skygazers will witness the closest full moon, or “supermoon,” of 2016. But more excitingly, it’ll be the closest full moon since 1948—and we won’t get another one like it until 2034. The reason the moon appears to shrink and grow in the sky is that its orbit is not a perfect circle, but rather, a modest ellipse.