Perseids Meteor Shower

The annual Perseid Meteor Shower is building and is due to reach its maximum this coming Sunday evening (11th to 12th August). A great shower to stay up and watch in the warmer summer months and as it builds up and fades out over several days, you can have a look out anytime the cloud disappears over the next few nights. The Moon is reasonably well-placed dropping below the horizon by 11pm at the peak so it doesn’t hide so many of the dimmer meteors.

The apparent source of the meteors in the sky is called the Radiant

The meteors themselves will appear to come from a point in the northeast between the constellation of Perseus and Camelopardis (the radiant). This is just to the left of the W of Cassiopeia. This is where the Earth is interacting with the cloud of meteoroid debris left by Comet Swift-Tuttle. The actual meteors may appear anywhere in the sky but follow their trail back and they will have originated around Perseus, hence how they got their name.

Simulated Perseid Meteors can all be traced back to the same spot in the sky

To give yourself the best conditions for seeing meteors, setup in a dark spot away from streetlights and other sources of light pollution. If you can travel to a darker location, even better. Get comfortable as looking up can be hard on the neck. A deckchair or a garden recliner are great. Else aground sheet and a blanket. Make sure you’ll be warm enough as heat wicks away when you are stationary for a period of time. Finally, give your eyes 20minutes to become adapted to the darkness and avoid non-red headlights, torches, and phone screens. The highest meteor rates come after midnight and into the early hours, but they are visible before too.

Given that the human eye can see a maximum field of view of 130 degrees or so, the next challenge is where to look. A group of four people can watch most of the sky with good coverage (3 looking southeast, southwest, and northwest and one looking straight up). By yourself, it doesn’t matter too much, just don’t look within 45 degrees of the radiant (above Perseus) or too close to the horizon.

Try to avoid the greyed out areas when looking as counts there will be low

Being comfortable is key and not trying to move your head to see a wider area as invariably that doesn’t work. I like to look at a portion of the sky I don’t know too well so I can learn it. Keep a count of meteors that you see and check that the direction of the trail is back towards the radiant. If not, you might just have seen a sporadic meteor or one from a weaker shower. Some people record the length of the meteor trail, its path through constellations and its magnitude and send this data to the British Astronomical Association or similar. Most just love to count.