Observing alerts!
The American Meteor Society is a good place to start to learn how to observe both annual showers and the occasional, unexpected fireball.
Carpe Caelum Observer’s Guide
Most of the objects in our sky have their positions calculated well in advance. The planets, for example, never surprise us by showing up somewhere unexpectedly. But there are yet undiscovered objects such as comets and minor planets which can suddenly put on a good show. Check here for any such unanticipated observing opportunities.
Aurora Tonight? Check out the latest prediction here.