How to catch the Leonids

Astronomers are hoping for a good show tonight, with the sky expected to be filled with shooting stars from the annual Leonid meteor shower.

The Leonids, which get their name because they appear to come from the constellation of Leo, occur when the Earth passes through the dusty debris left by Comet Tempel-Tuttle.

Small fragments of material, mostly no larger than a grain of sand, scorch through the Earth's atmosphere at 72 km/s (150,000 mph) and burn up. This produces a streak of light in the sky.

The show is usually at its best just after the comet has visited the inner Solar System - something it did early last year.

But predicting meteor storms is never easy. The 1998 event did not live up to the forecasts and most experts were also caught out by its timing - the storm turned up 14 hours earlier than expected.

Height of the storm

Astronomers hope for better this year, with perhaps 20 meteors a minute at the height of the storm.

Unlike last year, Europe should be in the best position to view the Leonids but wherever you live it is worth having a look at the night sky over the next 48 hours.

The best time to look is from 2300 local time onwards, with the peak expected around 0200 GMT (0300 Central European Time).

The European Space Agency (Esa) has this advice for anyone planning to spend the night skywatching:

• Try to find a dark, clear place to watch from as light pollution in a town can severely limit the number of meteors seen.
• You need no special equipment - do not use a telescope or binoculars - but do give your eyes time to adjust to the dark.
• The best way to observe a meteor shower is simply to lie back and look with your eyes alone. A deck chair or sun-lounger will make thing more comfortable.
• Set up your chair so that you are facing roughly south-east, and adjust your position so that can comfortably look at an angle halfway between the horizon and overhead. This will let you see the full radiant effect (the meteors appear to come from the constellation of Leo). But, in truth, if the storm does live up to expectations, you should see plenty of action no matter in which direction you look.
• Do not forget to wrap up warm.

And if you are on the wrong side of the world, or if it is a cloudy night in Europe, watch it on the web. Esa and other organisations have webcams pointed at the sky at various locations across the globe.

The weather looks as though it will be kind for most parts of the UK. Certainly, the central areas of the country should have reasonably clear skies for the event - even if that does mean freezing temperatures.

Unfortunately, Northern Ireland and the South West will be cloudy with outbreaks of rain and sleet. Further wintry showers in the East mean skywatchers on that side of the country may not get a very good view of the shooting stars either.

Central UK should have the clearest skies