Leonids

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Image:1966 leonids big.gif The Leonids are a prolific meteor shower associated with the comet Tempel-Tuttle. The meteor shower is visible every year around November 17 when the Earth moves through the Leonid meteor stream. The stream comprises solid particles, known as meteoroids, ejected by the comet as it passes by the Sun. A typical particle is no bigger than fine dust, and burns into oblivion with a streak of light as it hits Earth's atmosphere at tremendous speed (71 km/s). The Leonids get their name from the location of their radiant in the constellation Leo: the meteors appear to stream from that point in the sky.

The Leonids are famous because their meteor showers, or storms, can be among the most spectacular. In most years the rate at which meteors are likely to be seen is not great; however, years of highly elevated rates tend to follow a 33 year cycle, associated with the 33 year orbit of Comet Tempel-Tuttle. Storms in peak years can feature thousands of meteors per hour; notable events were observed in 1698, 1799, 1832, 1833, 1866, 1966, 1999, 2001 and 2002. During a strong storm in dark viewing conditions the sky can appear to be "raining stars".

Given the size of the particles, undetectable with telescopes, the precise timing and rate of each year's shower is challenging to predict. However, a close encounter with Jupiter is expected to perturb the comet's path, making storms of historic magnitude unlikely for many decades.

See also

• Meteor showers
• List of meteor showers
• Stars Fell on Alabama, based on the 1833 Leonid shower

External links

• Leonid History by Gary W. Kronk
• NASA: Background facts on meteors and meteor showers
• NASA: Estimate the best viewing times for your part of the worldaf:Leoniede

ca:Leònides de:Leoniden es:Leónidas (astronomía) fr:Léonides ko:사자자리 유성우 it:Leonidi he:לאונידים nl:Leoniden ja:しし座流星群 pl:Leonidy pt:Leónidas (chuva de estrelas) ru:Леониды sk:Leonidy sv:Leoniderna uk:Леоніди zh:狮子座流星雨