Tonight begins the peak of the annual Ursid Meteor Shower, the spectacular event, caused by dust particles left behind by Comet 8P/Tuttle. It always peaks near the time of the December Solstice (Winter Solstice) which in Pittsburgh happens today Thursday, December 21, 2017 at 11:27 AM. Experts are calling for the Ursids to peak on the night of the solstice itself, tonight December 21 this year. Best viewing is suggested to be on the morning (tomorrow) of December 22. The waxing crescent moon will set in the evening, providing moon-free viewing for the rest of the night. This shower favors more northerly latitudes in the Northern Hemisphere. The expected rate per hour is 5-10 meteors, but bursts of 100 or more meteors per hour have been observed at times, over the past century. Remember as in watching any meteor shower allow a minimum of 15-20 minutes to allow your eyes to become dark accommodated and try to locate your viewing under clear and dark skies!