The Perseids are a regular annual event and one of the most reliable meteor showers, with the meteors apparently coming from the direction of the constellation of Persius.

It occurs every year because as the earth orbits the sun, it passes through dust particles left by a comet. As it takes a year for the earth to orbit the sun, it passes through this debris field at the same point every year. The Swift-Tuttle comet which left the trail orbits the sun every 130 years, and the particles have mostly been there for thousands of years.

As these small particles hit the earth's upper atmosphere they burn up, producing the 'shooting star' streak of light in the night sky.

When there are clear skies and the moon is not so strong that it washes out faint meteors, around 60 or more an hour can be seen. On August 12 2010, the moon should have very little effect on the night sky - setting before the meteors are active - making it a good night for spotting meteors.

Strong light from artificial sources such as streetlights make it more difficult to see meteors, so watching from a more rural location makes it is more likely to see them.

The best time to see them are in the pre-dawn hours, as at that point the earth is turning towards the sun and that side of the earth is hit by more debris as the earth travels through space.

Looking for the meteors does not require any special equipment like binoculars or a telescope, as most will be visible with the naked eye.