THE PERSEID METEOR SHOWER IS BEGINNING: This week, Earth is entering a stream of debris from Comet 109P/Swift-Tuttle, source of the annual Perseid meteor shower. Specks of dusty debris hitting the top of Earth’s atmosphere faster than 110,000 mph are burning up in the night sky, producing a spray of shooting stars from the constellation Perseus. Meteor rates are relatively low now, but they will increase sharply in the nights ahead. Forecasters expect the shower to peak on Aug. 11-13 with perhaps dozens of meteors per hour visible in bright moonlight. Visit Spaceweather.com for observing tips and sky maps.