Meteor showers are celestial events where meteors radiate from a single point in the night sky, caused by streams of cosmic debris (meteoroids) entering Earth's atmosphere on parallel trajectories—most are smaller than a grain of sand and disintegrate harmlessly. Historically viewed as an atmospheric phenomenon, Ernst Chladni proposed in 1794 that they originate in outer space, a theory confirmed by the Great Meteor Storm of 1833, when Denison Olmsted showed the Leonids radiated from the constellation Leo. In 1866, Giovanni Schiaparelli linked meteors to comets by matching the Leonid shower's orbit with Comet Tempel, and Fred Whipple later (1951) described comets as "dirty snowballs" that shed debris. Ancient records show observations from Sparta (1200 BCE), China, Japan, Korea, and the Timbuktu manuscripts (1583), with the Lyrids being the oldest continuously recorded shower (China, 687 BCE). The Meteor Data Centre lists over 900 suspected showers (about 100 well-established), and intense events called meteor storms (like the Leonids) can produce over 1,000 meteors per hour, with NASA maintaining a daily map of active showers.