The beginning of May is marked by a sky show across Australia.
The annual Eta Aquariids meteor shower peaks in the early morning this Friday May 5 and Saturday May 6.
But you need to set your alarm clock. The best time to see them is between 3:00 am and 5:00 am.
The Eta Aquariids are the second best meteor shower of the year for Australian sky watchers, said Jonti Horner, an astronomer at the University of Southern Queensland.
"This year's shower will be a bit of a mixed bag," Professor Horner said.
On one hand, there is the possibility of a lot more meteors than usual, but the shower also coincides with the full moon — and a lunar eclipse — on May 6.
The bright moon will make it harder to spot fainter meteors, said amateur astronomer Ian Musgrave.
"The full moon is on the other side of the sky, but it's still going to drop the rates down," Dr Musgrave said.
Here are his predictions for the number of meteors per hour for each capital city between May 4 and 7.
Morning May 4 |
Morning May 5 |
Morning May 6 |
Morning May 7 |
|
|---|---|---|---|---|
Adelaide |
10/hr |
10/hr |
8/hr |
6/hr |
Brisbane |
10/hr |
11/hr |
8/hr |
6/hr |
Canberra |
10/hr |
11/hr |
8/hr |
6/hr |
Darwin |
11/hr |
12/hr |
9/hr |
6/hr |
Perth |
10/hr |
11/hr |
8/hr |
6/hr |
Melbourne |
9/hr |
10/hr |
8/hr |
6/hr |
Hobart |
9/hr |
9/hr |
7/hr |
5/hr |
Sydney |
10/hr |
11/hr |
8/hr |
6/hr |
But there could be more ...
Some scientists predict this year and next year's Eta Aquariid meteor showers could be unusually active, Professor Horner said.
The Eta Aquariids are created by Earth moving through a debris stream laid down over time by Halley's comet — but we could be about to move through denser patches of the stream.
Laid down more than 2,000 years ago, in 390 BC as well as 829 BC, these denser patches have been prevented from spreading out by the gravitational pull of Jupiter.
"Because there is more dust ... the number of meteors we see is higher," Professor Horner said.
If the modelling is correct, we should hit one of these patches in the early morning of May 5.
"Look out on Friday and Saturday morning for the best rates," Professor Horner said.
But, it was impossible to know from the predictions alone how strong — or not — any outburst would be, he said.
On the plus-side, the Eta Aquariids are fast-moving, which makes them appear brighter.
"High speed doesn't guarantee lots of bright meteors, but any meteor of a given size will be brighter than what it would be if it was slower," Professor Horner said.
While the Moon will wash out fainter meteors, it will be low in the sky in the hour or so before dawn.
And if this year's meteor shower turns out to be a fizzer, there's always next year.
"The shower in 2023 will give us an idea of what to expect in 2024, which some researchers have predicted will be the best Eta Aquariid display of the coming century," Professor Horner said.
And there won't be a pesky Moon getting in the way next year either.
How to see the meteors
The best time to see the meteor shower is between 3:00 am – 5:00 am.
At that time, the point in the constellation of Aquarius that the meteors appear from will be high above the northern horizon.
"The sky there doesn't have much 'pretty' in it, but you've got bright Saturn in a nice position," Dr Musgrave said.
To spot meteors you need to scan the sky, rather than look at a point.
"The meteors are fast, with a few fireballs and persistent trains," Dr Musgrave said.
If you have a telescope you might want to check out Saturn.
"Saturn is exceptionally pretty through a telescope," Dr Musgrave said.
"At the moment the rings are closing up, so the angle of tilt is getting narrower and narrower."
But don't spend too much time looking through the telescope or you'll miss the meteors whizzing by.
And you'll need to find a spot where you can block out the Moon.
"If you've got the Moon in your field of view, your night vision is blocked out even more," Dr Musgrave said.
Lunar eclipse
If you're up in the early hours of May 6 to check out the meteors you might notice the Moon looks a bit weird (if you have super-good eye sight).
Just two weeks after a solar eclipse, there is a lunar eclipse over Australia.
Lunar eclipses occur during the full moon phase when the Sun, Earth and Moon line-up (syzygy) and Earth's shadow passes across the Moon.
Because the Moon's orbit is tilted, the Earth, Moon and Sun don't always line up perfectly — so in this case it only moves through the outer part of Earth's shadow (the penumbra).
Unlike total or partial lunar eclipses, the Moon doesn't noticeably change colour during a penumbral eclipse. At best you might notice a bit of a greyish shadow across its northern pole.
"If you are watching the meteors, you might catch the eclipse as well, although you will ruin your night vision," Dr Musgrave said.
Here are the times across Australia (and unlike the solar eclipse, a lunar eclipse is safe to look at):
6 May |
Eclipse begins |
Max |
Eclipse ends |
|---|---|---|---|
AEST |
1:14:11 am |
3:22:59 am |
5:31:45 am |
ACST |
12:44:11 am |
2:52:59 am |
5:01:45 am |
AWST |
11:14:11 pm (May 5) |
1:22:59 am |
3:31:45 am |
