| Term: | Meteor showers |
| Definition: |
An increased number of meteors all appearing to diverge from the direction of a single point, called radiant. Meteor showers occur annually on the same dates, when the Earth crosses through a meteoroid stream. Meteor showers are named after the constellation in which the radiant is located. For example, the Perseids's radiant lies near the top of the constellation Perseus. Most meteor showers are caused by comets. As a comet orbits the Sun it sheds an icy, dusty debris stream along its orbit. When the Earth's orbit intersects the dust trail, more meteors are seen as the cometary debris encounters our planet's atmosphere. In the case of the Geminids and Quadrantids, those meteor showers come from the debris scattered by orbiting asteroids. Typical meteor showers show 15 to 100 meteors per hour at their peak. On very rare occasions, during a meteor storm, thousands of meteors fall per hour. Prominent meteor showers are: Quadrantids, Lyrids, Eta Aquariids, Delta Aquariids, Perseids, Orionids, Taurids, Leonids, Geminids, Ursids, Alpha Capricornids. |