The Leonids form a meteor ( shooting star power ), which can be observed in November. His radiant lies in the constellation of the Lion (Latin: "leo " = " the Lion" ), about 10 degrees north of the star Regulus. Its origin is the comet Tempel-Tuttle, which leaves in its orbit around the sun countless fragments ( meteoroids ). Crosses the Earth's orbit so great a cloud of fragments, and get them into the Earth's atmosphere, they burn up and can be perceived as shooting stars ( meteors ).

The sharp peak of activity is observed on the night of 17th to 18th of November. The shooting stars are extremely fast with a geocentric velocity of about 71 km / s. Once the Leonidenstrom was much more active than it is today, so was seen as shooting stars per se month in previous times of November. Meanwhile, the debris cloud of the comet's origin is, however, already spread very far, so the current has only one more weakly pronounced maximum in the rule.

Every 33 years, it may come to a special spectacle: Cross the Earth 's orbit of the comet Tempel-Tuttle shortly after it has passed through the inner solar system, the number of visible Leonids meteors is particularly large. It then comes to a meteor storm with thousands of meteors per hour as it was for example the case in 1966. In November 1833 should have been observed per hour even up to 200,000 shooting stars.