(CNN) – The Eta Aquariid meteor shower is expected to peak on Tuesday, but a nearly full moon could outshine the show. May is the best spring month to view meteor activity for those in the northern hemisphere, according to the American Meteor Society. However, this meteor shower favors sky watchers in the southern hemisphere, where between 20 and 40 meteors can be seen each hour. The source of the Eta Aquariid meteor shower is Halley's Comet. This happens again in October, which creates the Orionid meteor shower.