SKYGAZERS are preparing for the high point of the annual Perseid meteor shower.
The shower, which reaches its peak today, occurs when the Earth passes through a stream of dusty debris from the comet Swift-Tuttle. As this cometary "grit" strikes our atmosphere, it burns up, often creating streaks of light across the sky.
The meteors appear to come from a point called a "radiant" in the constellation of Perseus – hence the name Perseid.
As usual, amateur skywatchers will be rigging telescopes and getting out binoculars to enjoy the display, which could see as many as 50 to 80 meteors streaking overhead every hour.
"Earth passes through the densest part of the debris stream some time on 12 August. Then, you could see dozens of meteors per hour," said Bill Cooke of Nasa's meteoroid environment office.
Meanwhile, a group of British amateur astronomers has boldly gone where no star-gazers have been before, turning the phenomenon into a global social event with the help of the Twitter networking site.
Newbury Astronomical Society says its "meteor star party" will include thousands of guests from all over the world "tweeting" images of the Perseids, as well as the Moon, Jupiter and other celestial objects.
The "Twitter Meteorwatch" follows on from a "Twitter Moonwatch", organised by the astronomical society in May.
Richard Fleet, president of the society, said: "We realised early on that what people want are images of the night sky, so we used our array of telescopes and cameras to provide a constant stream of pictures, which we uploaded straight to Twitter.
"We were amazed at how excited people were about our Twitter Moonwatch; we had thousands of people who had probably never looked through a telescope before asking us questions directly and viewing images."
The mass participation event is planned as part of the International Year of Astronomy.
Shooting stars occur as small particles, often no bigger than a grain of sand, enter the Earth's atmosphere at high speed and burn up.
A quarter moon will mean the sky is not as dark as it could ideally be, but the meteors should still put on an impressive display.
The National Trust has published online guides to seven top Perseid viewing sites, including coastal spots, nature reserves and national parks.
Jo Burgon, head of access and recreation at the trust, said: "Light pollution from our towns and cities has increased so much in recent years, but head out to the countryside for the perfect place to explore the beauty of the night sky, away from the intrusive glow."
THE best time to see the Perseids is during the early hours of today and tonight.
No special equipment is required to watch the sky show. Astronomers say binoculars might help but will also restrict the view to a small part of the sky.
Stargazers are advised to lie on a blanket or a reclining chair to get the best view.
Robin Scagell, vice-president of the Society for Popular Astronomy, said: "You can look anywhere up in the sky at about a 50-degree angle, or comfortable eye height. South is as good a direction as any. Under good conditions you might see one meteor every few minutes, or one or two a minute if you're lucky."