This is the first day of summer in the northern hemisphere, and the first day of winter in the southern hemisphere. The Sun will have reached its northernmost position in the sky, with the north pole tilting towards the sun.
The Perseids are a prolific meteor shower associated with the comet Swift–Tuttle. The Perseids are so called because the point from which they appear to come, called the radiant, lies in the constellation Perseus.
The Leonids are a prolific meteor shower associated with the comet Tempel–Tuttle. The Leonids get their name from the location of their radiant in the constellation Leo: the meteors appear to radiate from that point in the sky.