This week, Earth is passing through a stream of debris from an unknown source, and the encounter is causing a meteor shower in broad daylight. The shooting stars are mostly invisible to the human eye. Astronomers know the shower is underway because the meteors reflect radio waves. According to data from Canada's Meteor Orbit Radar (CMOR), there is a hot spot of activity right now in the constellation Aries not far from the sun: This happens every year in early June, and the resulting Arietid meteor shower typically peaks on June 7th. If you could turn off the sun, you would see more than 60 meteors per hour, making it one of the most active showers of the year. No one is sure where Arietid meteoroids come from, although some astronomers suspect they are debris from sungrazing asteroid 1566 Icarus. Another candidate is comet 96P/Machholz. In fact, there is way to see a few of these meteors. Try looking just before sunrise. The shower's radiant (labeled ARI in the radar map above) rises