Leonids

An annual meteor shower, the radiant of which lies within the "sickle" in the constellation Leo. The peak occurs on 17 November and the normal limits are two days either side. Though a small number of meteors are detected each year, spectacular displays are occasionally seen. The Leonids in 1966 gave observers in the USA the richest shower ever recorded, with rates as high as 40 meteors a second. The shower is associated with Comet 55P/Tempel-Tuttle, first recorded in 1865, which has a period of 33 years. The meteoric material is concentrated near the comet and is not evenly spread around the orbit. Good displays are possible only every 33 years, though they are not necessarily seen even then, if the comet passes too far from the Earth's orbit.