Auroras are a special Betweenlands weather event that can occur quite rarely. It will cause streaks of varying neon light, called auroras, to appear very high in the Betweenlands sky. This event is almost purely visual. However, during the event, Will o' the Wisps will not disappear even when a player is close to them, allowing them to collect the wisp as an item.
Auroras can be manually triggered using the following command: /blevent <toggle/on/off> auroras