Starwatch: the Perseids – our most reliable meteor shower

One astronomical event dominates all others this week. It is the annual Perseids meteor shower. This is a reliable meteor shower that can reach peak rates of one meteor every minute. The meteors are dust grains that were ejected as part of the tail of comet Swift-Tuttle, which orbits the sun once every 133 years. Because of the size of the dust stream, Perseids can be seen from 17 July to 24 August. However, the peak of the shower is expected to occur this year in the early hours of 13 August, so that is the night to observe. From London, the bright moon sets around 03:14 BST allowing an unimpeded view of the shooting stars. Before then, the moon will already be low in the early hours and the brighter meteors will cut through. The meteors are called the Perseids because they radiate from a point in the constellation Perseus. The chart shows the view looking east at 02:00 BST 13 August.