If you want to see the Perseids Meteor Shower, then tonight is probably your best bet. If you look towards the north (or towards the constellation of Perseus, if you happen to know where that is) you could see as many as sixty meteors an hour. Another good time to look would be before dawn tomorrow. They are best seen in the northern hemisphere.
These meteorites are fragments from a comet called Swift-Tuttle which passes us by every 133 years. It leaves a trail of tiny pieces of itself all along the path of its orbit. In late July and early August our planet passes through this trail and some of them are drawn into our atmosphere. The fragments are mostly only about the size of a pea and few ever reach the ground. They burn up at a height of around 60 to 80 miles above our heads. What makes them visible is the reaction of the gases in the atmosphere to the friction caused by the meteor falling through it at thousands of miles an hour.
I mentioned on August 10th that the Perseids are sometimes known as the Tears of Saint Lawrence because they appear around the same time as the saint’s feast day. In earlier times, the Romans believed that the meteor shower was the ejaculation of Priapus, one of their gods of fertility, and that he was fertilising the fields. Priapus is always represented as a man with an enormous erection. He is a rural god who is associated with both agricultural fertility and general protection from the evil eye. For this reason there are many Roman artefacts which represent him. Either that, or the Romans just thought it was funny.