Perseid meteors promise free firework show

Comet dust to light up the skies

Star gazers are in for a treat this week, if the clouds clear, as the Perseid meteor shower builds to its peak of activity.

The Perseid meteors are an annual show, starting in late July when Earth enters a cloud of debris from the tail of Comet Swift-Tuttle. This year we’ll also cross the path of a new strand of debris that separated from the comet in 1862.

Because this strand of debris is still so young, the dust particles are still relatively concentrated. This means that when we pass through it we’ll be treated to a more brilliant display than usual. Over time (lots of time) the strand will disperse and become indistinguishable from the main cloud.

At around 9pm GMT on the 11 August, we’ll enter this younger strand, and could see as many as 200 meteors per hour. The extra shooting starts will be visible from Europe and Asia, but stargazers in the US will have to wait for their show until the normal annual peak of activity – around 50 per hour - the following day.

The comet Swift-Tuttle was actually discovered because of the strand of material boiling off from the comet. Two American Astronomers, Lewis Swift and Horace Tuttle, working independently, made the discovery.

In 1992, it seemed as if the comet was Earth-bound, set for an impact with out planet in 2126. Newer calculations suggest this is not going to happen and that the comet will pass by 15 million miles away.

On average, a Perseid meteor will be about as bright as the stars in the big dipper – so if you can get out of the brightest urban areas, you stand a good chance of seeing them. ®

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