Grab a deckchair, camera and some friends and celebrate the end of the year with some cosmic sparklers.
The annual Geminid meteor shower is back, peaking on Wednesday evening and early Thursday morning.
The Geminids are always a really good shower, amateur astronomer Ian Musgrave says.
"This will not be as good as previous years because of the moonlight, but it will still be thoroughly enjoyable."
The trick this year is to catch the Geminids before the Moon rises, says Jonti Horner, an astronomer at the University of Southern Queensland.
"If you want dark skies, particularly if you want to do photography and try and get good photos, doing that before the Moon rises is a good plan," he said.
That means the best time to start looking for meteors this year is mid to late evening, about one to two hours before moonrise.
The Moon rises at the following times during the peak on Wednesday night/Thursday morning (depending on your time zone):
- Adelaide 12:52am ACDT (Dec 15)
- Brisbane 11:12pm AEST
- Canberra 12:40 am AEDT (Dec 15)
- Darwin 11.53pm ACST
- Hobart 1:01am AEDT (Dec 15)
- Melbourne 1:01am AEST (Dec 15)
- Perth 11.50pm AWST
- Sydney 12:29am AEDT (Dec 15)
Late evening vs early morning
The Geminids are created as Earth moves through the debris of an asteroid called 3200 Phaethon.
From the perspective of a stargazer on Earth, meteors appear to radiate from a point near the bright star Castor in the constellation of Gemini.
The meteor show starts once that point rises above the north-east horizon in the night sky.
This year, bright-red Mars is also in that area of the sky, forming a triangle with two red stars Aldebaran and Betelgeuse.
Unlike many other meteor showers, you don't need to set your alarm clock to start seeing some action, with the Geminids (although the rates are lower and they can be trickier to see when the point is close to the horizon).
"One of the beauties of the Geminids is you can see them from the mid-evening onwards," Professor Horner says.
Usually, you'll see the most meteors when the radiant is high in the sky towards 2am (local time), but this year the Moon rises about two hours after the Geminids radiant.
"What that means is you've got about a two-hour period when you'll get good, dark skies to view the Geminids, and you'll see the rates building as the radiant gets higher in the sky."
If you're out later you'll still see meteors once the Moon rises; it just becomes a trade-off.
"Once the Moon rises it will eat into the rates, but they will still stay quite good because the radiant is getting higher in the sky until about 2am," Professor Horner says.
Luckily, the Moon will be in its last quarter, plus the Geminids usually has a number of bright meteors that not even moonlight can wash out.
"The Geminids tend to produce so many meteors it will have a decent number of bright ones anyway," he says.
How many will I see?
The meteors are visible right across Australia, but the further north you are, the better.
Here is a rough guide to the rates you may see from your location between 11:30pm and 2am (local time) over the next three nights, adjusted for the impact of the Moon.
Location |
13/14 Dec |
14/15 Dec |
15/16 Dec |
|---|---|---|---|
Adelaide |
9/hr |
18/hr |
5/hr |
Brisbane |
10/hr |
25/hr |
6/hr |
Canberra |
8/hr |
18/hr |
5/hr |
Darwin |
14/hr |
33/hr |
9/hr |
Hobart |
6/hr |
12/hr |
3/hr |
Melbourne |
8/hr |
16/hr |
4/hr |
Perth |
10/hr |
18/hr |
4/hr |
Sydney |
9/hr |
20/hr |
5/hr |
Light pollution in urban areas will cut down the rates, but Professor Horner says people living in the city should still be able to see a few bright ones.
"You will be able to see them from your balcony, but if you are really keen, find somewhere local that's a bit darker where you are away from streetlights."
Tips for viewing
Spotting meteors is like watching slow TV, Professor Horner says.
"The good rule of thumb is meteors are like buses; you can wait 10 minutes and three come along at once," he says.
"It's that randomness that makes it quite compelling."
Professor Horner advises taking a comfortable chair or something to lie down on, and warm clothes even though it's summer.
Make sure you have a good view of the east and the north in the evening, or the north-west if you are out in the early morning.
After giving your eyes some time to adjust, scan the sky rather than look for the point. And be patient.
"I can almost guarantee [that] if you just look for five minutes, you'll be disappointed," he says.
"Lay back, share it with other people, chill out, and you'll see what you see."
