Monday, July 31, 2017
Australian Perseid Meteor Shower - Morning August 13, 2017
You may have seen Facebook posts (or twitter notifications ) saying that on August 12/13 there will be a meteor shower that will be the brightest ever seen by mankind with Thousands of shooting stars. Well nope. This is the Perseid meteor shower, and though a reliable and good northern hemisphere shower, and hundreds of meteors may be seen under the best condition, this year the just bright waning Moon is in the sky above the meteor radiant, so rates will be lower than usual.
The Perseid Meteor Shower runs from July 17–August 24, and peaks in the early morning between Saturday August 12 - Sunday August 13 AEST. The midpoint is 20 H UT on the 12th (6 am AEST). See the International Meteor Calendar for 2017 for further details.
Despite this being a quite reasonable meteor shower in the northern hemisphere, for most of Australia the radiant is below the horizon, and only the very occasional meteor will be seen shooting up from the northern horizon. Only observers in northern Australia (at the latitude of Brisbane or further north) will have decent rates.
This is a poor year, while the peak occurs after sunrise in Australia, it still occurs reasonably close to radiant maximum height and while this years peak is higher than usual (with a ZHR of 150 meteors per hour predicted) the bright waning Moon will substantially reduce the number of meteors you can see.
However, these ZHR predictions are ideal rates for sites with the meteor radiant directly overhead, under the darkest possible skies with nothing obscuring the sky. From Australia, we will see much lower rates than these ideal ones. Anyone south of Brisbane will see only the occasional meteor, say maybe one or two per hour (or less), the further north of Brisbane you are, the more meteors you will see.
People around the latitude of Darwin have the best chance of seeing meteors, possibly as many as one every 5 minutes at the peak (see table below). Next is places with the latitude of Cairns (around a meteor every 6 minutes), then with the latitude of Mackay (like Port Headland and Mt Isa), and the places with the latitude of Alice Springs (again,see table below).
To see the meteors, you will need to be up from around 3:00 am local time on the 12th, 13th or 14th (yes, a really horrible hour of the morning), with best views 4:00 am-5:30 am on the 13th. The meteor shower will be located due North, with the radiant just above the northern horizon (see charts above). Cloud cover predictions can be found at SkippySky.
When you get up, allow at least 5 minutes for your eyes to adjust, and be patient, it may be several minutes before you are rewarded with you first meteor, then a couple will come along in quick succession. Choose a viewing spot where you can see a large swathe of sky without trees or buildings getting in the way, or with street lights getting in your eyes. The darker the spot the better (but do be sensible, don't choose a spot in an unsalubrious park for example).
A lawn chair or something similar will make your observing comfortable (or a picnic rug spread on the ground and a nice pillow), and having a Thermos of hot coffee, tea or chocolate to swig while watching will increase your comfort. (Here's some hints on dark adaptation of your eyes so you can see meteors better).
The following table show the predicted peak rates at around 5 am local time on the mornings of the 12th, 13 and 14th of August for a number of cities under dark sky conditions. Rates will be similar at the same latitude as these cities, and rates will be intermediate at spots between these cities.
|Town||Morning August 12||Morning August 13||Morning August 14|
|Alice Springs||3 meteors/hr||6 meteors/hr||4 meteors/hr|
|Brisbane||2 meteors/hr||3 meteors/hr||2 meteors/hr|
|Cairns||5 meteors/hr||10 meteors/hr||7 meteors/hr|
|Darwin||8 meteors/hr||13 meteors/hr||9 meteors/hr|
|Mackay||4 meteors/hr||7 meteors/hr||5 meteors/hr|
Rates on the morning of the 15th are similar to that of the 14th. Note, those of you who have Stellarium, in version 13 they have added meteor shower radiants (rates set in the planets dialogue, F4). However while the radiants are shown, the simulated meteors come from random points in the sky, not the radiants.