Meteor showers happen on an annual basis. Using Wolfram|Alpha, investigate these events, which are the result of the Earth plowing through swarms of dust left behind by comets and asteroids that periodically cross the Earth's orbit. As this dust hits the atmosphere, it heats up and glows due to friction, causing a bright streak sometimes also called a "shooting star" or "falling star." Meteor showers are named after the point in the sky from which they appear to originate, known as the radiant. This point appears in a specific constellation, so the Perseid meteor shower appears to originate from the constellation of Perseus, the Geminid meteor shower from Gemini, the Lyrid meteor shower from Lyra, etc. Meteors can appear almost anywhere in the sky, but they always appear to radiate from their radiant constellation and can last for hours or days around their peak.