The Wanderer

The night sky above Wyrring is typically dominated by the single large moon which circles the planet. However, approximately every 2,000 years, a second, smaller moon can be spotted. This moon, referred to as "the Wanderer", travels far outside the solar system, only to return after significant periods have passed. It hasn't returned in recorded history, and scholars have only roughly translated historic records to confirm both its existence and the effects it has during it's visit. Ancient civilizations appeared to treat it as a herald of doom, and natural disasters, such as extreme tides and tsunamis, earthquakes, and fires follow shortly after it's appearance.