Here come the Perseids!
10 August 2015
Sky watchers will be in for a treat this week, when the annual Perseid meteor shower reaches its peak! If you've never seen a meteor before, this is the ideal opportunity. Maximum activity is expected between 11 and 13 August. Keep away from bright lights, let your eyes adapt to the darkness, and lie back and stare at the sky!
Perseids are named after the constellation of Perseus, from which they seem to radiate outwards. However, they can appear anywhere in the sky. The best direction to look is wherever your sky is darkest, probably straight up. The shower is best observed from 11 pm or midnight onwards, when you may see up to 100 meteors per hour!
The Perseids are sand- to pea-sized bits of rocky debris that were ejected long ago by comet Swift-Tuttle. This comet is slowly disintegrating as it orbits the Sun. Over the centuries, its crumbly remains have spread along its orbit to form a stream of particles hundreds of millions of kilometres long.
Earth’s path around the Sun carries us through this comet debris every mid-August. The particles, called 'meteoroids', are travelling at 60 km per second with respect to Earth. When one of them hits the upper atmosphere, it creates a white-hot streak of superheated air. Occasional brighter ones survive for several seconds, leaving trails of glowing smoke and gas.
The Perseids are ideal for digital imaging. Attach your camera to a tripod, preferably with a wide angle lens and a high ISO (darkness) setting. Keep the shutter open for 10-15 seconds at a time (longer in a really dark place). With a bit of luck, you should capture one or more Perseids streaking across the photo!