The last time Comet Tempel-Tuttle passed Earth, in 1966, meteors rained down at a rate of 150 000 an hour at the height of the storm. There were only a few hundred satellites orbiting the Earth at that time, but three decades on you can hardly move for satellites in low Earth orbit and shuttle flights are commonplace.

Tempel-Tuttle is temperamental, however, and no one is ever entirely sure how spectacular a display it will put on. As the comet approaches Jupiter and Saturn, the planets’ gravitational pull can deflect its orbit, altering the course of its dusty tail and determining whether the Earth passes through the densest area of cometary debris. This variability makes it difficult to predict the intensity of the storm in 1998.

The best astronomers can do is record the increase in the number of meteors seen in the November skies each year and compare these figures with those in the years running up to past cometary encounters. From this they can assess the risk to shuttles and satellites during the next encounter.

The British Astronomical Association and the telephone information service Science Line have joined forces to encourage people to help count the meteors. Leonid Watch 95 is the brainchild of John Mason, president of the association. “The more people across the world we can encourage to help the better,” he says. “That way, if it’s cloudy in one part of the world, at least we have a chance of some measurements from elsewhere.”

Leonid watchers must count the number of shooting stars they see in blocks of 30 minutes, at any time between 14 and 20 November. Normally, the rate is between 5 and 20 an hour, but as 1998 approaches this should increase as Comet Tempel-Tuttle nears the Earth’s orbit, shunting its clouds of dust and debris in front of it.

Mason predicts that this year the rate might be between 50 and 100 an hour, and in the next few years it could reach the phenomenal rate seen in 1966. There is nothing satellite companies can do to protect hardware that is already in orbit. But NASA might well have to think about rescheduling its shuttle flights.

For an information pack, send a large stamped addressed envelope to Leonid Watch 95, PO Box 7, London W5 2GQ. For more information call the Science Line on 0345 600 444 between 1 pm and 7 pm, Monday to Friday.

The problem is also on the increase in Britain, with 18 such crimes in Surrey alone at the end of last year. The AA became the latest victim just before the New Year when thieves stole processors and memory chips from 1340 machines in its Basingstoke offices.

Chips are all too easy to launder on black markets in the Far East, where they are more valuable than heroin, and through the growing computer cottage industries in Britain. Intel is already placing serial numbers on its more expensive microprocessors and has started to place tracking devices in some of its products. The company announced this week that it will also be working with the semiconductor industry on a standard bar code identification system for computer chips, making them as identifiable as a human fingerprint and a lot less attractive to buyers on the black market.