16 November 2012 - The annual Leonids meteor shower is in progress, due to peak late tonight and early tomorrow morning with a likely rate of about 10 or so meteors per hour. Unfortunately, cloudy skies over much of the UK look set to disrupt viewing until Saturday night / Sunday morning.
The Leonids are usually one of the more prolific annual meteor showers, with fast, bright meteors associated with Comet Tempel-Tuttle. The radiant (the point where the meteors appear to stream from) is at the head or 'sickle' of the constellation Leo (the Lion). Leonid meteors can be seen each year over a period of several days centred around 17 November. Some leave trails which can last for up to half an hour.
About every 33 years (the period of Comet Tempel-Tuttle), the Leonids produce meteor 'storms' when hundreds or even thousands of shooting stars can be seen. Such storms were seen in 1799, 1833, 1866, 1966 and 1999-2001 (although the expected 1899 and 1933 storms were disappointing). The 1833 storm was particularly spectacular, with an estimated 100,000 meteors per hour. The 1999-2001 storms produced about 3000 per hour.
Image: Leonid shower; photo by Thomas Paulech and Juraj Toth, Bratislava, Slovakia