SPORADICS, SHOWERS, AND STORMS
On any moonless night, you should be able to see four or five meteors per hour. These unexpected shooting stars— or sporadic meteors—can appear anywhere in the sky. Their rate tends to increase from local midnight until dawn, when the observer's location is carried toward Earth's leading orbital edge and placed in the path of more interplanetary particles.
You never really know how many sporadics you will see, but some meteors can be anticipated. On certain nights each year, the rate of meteors not only increases, but the meteors appear to radiate from a particular region of the sky. These predictable displays are called meteor showers.
Compared with the 4 or 5 meteors per hour you can expect to see on any dark, moonless night, the 20 to 50 meteors per hour of a meteor shower might be considered a downpour. Even a shower, though, appears like a sprinkle next to the meteor storm. A robust meteor storm can pro-duce thousands of shooting stars per hour—sometimes 10 to 20 per second. Meteor storms, however, are rare events.