A crescent moon will appear alongside the bright stars Castor and Pollox to form a lopsided grin in the night sky on May 29.

NGC 7635, also called the Bubble Nebula, is an emission nebula lit from within by the hot, young star SAO 20575.

The best time to see noctilucent clouds is on clear nights between late May and mid-August, about 90 to 120 minutes after ...