Meteor Showers Meteor Showers Buzzwords sporadics intersect radiant On any night, if you watch the sky carefully, you can see a few meteors each hour. They are called sporadic meteors. But that takes a lot of effort and time. Several times a year, though, the earth passes through the path of a comet, and for a few hours tens, hundreds, or even thousands of meteors will streak across the sky in a meteor shower. Many meteor showers can be predicted, since they repeat every year when the earth returns to the same place in its orbit around the sun.
Scientists take careful measurements of where the earth is during a shower.
Then, by comparing those measurements to the orbits of comets, they can calculate which comet causes each shower. During a meteor shower most of the meteors seem to start near the same place in the sky, called the radiant. The meteor shower is usually named for the constellation the radiant is in. For instance, the meteor shower that has its radiant in the constellation Leo is called the Leonid shower. Check out the calendar of meteor showers in the yellow box to the right.