PERSEID METEOR SHOWER--THIS WEEK: Earth is entering a stream of debris from Comet Swift-Tuttle, source of the annual Perseid meteor shower. Forecasters expect meteor rates to peak at 100+ per hour on the night of Aug. 12-13 when our planet passes through the heart of the debris stream. Perseids produce more fireballs than any other meteor shower of the year, so stay tuned for a good show. [meteor radar]