If you’re planning to stay up late or go out on the town this weekend, you might see a couple of shooting stars across the sky.
The annual Orioides meteor shower is at its peak between the early hours of Friday, October 21 and Sunday, October 23, with the best rates expected in the early hours of Sunday morning.
“If you have a clear sky, you should see a few meteors,” says amateur astronomer Ian Musgrave.
The Orionids are created by the Earth’s movement through a debris trail left by Halley’s Comet, which also produces a meteor shower earlier this year known as the Eta Aquariids.
As the name suggests, the point in the sky where the Orion meteors come from, known as the radiant, is in the constellation Orion.
“I always love the Oronids because it signals the start of summer, bringing Orion back into the sky,” says Melbourne Planetarium astronomer Tanya Hill.
Orion is locked in a cosmic and mythological battle with Scorpius, who dominates the night sky during the winter months and disappears when Orion rises.
The bright spot of the Orioides meteor shower is between Mars and Betelgeuse around 2:30 a.m. on October 22. (Stellarium/Genelle Weule)
This year the celestial elements are aligned for a better than average show.
If you look up between 2 and 3 a.m., the waning crescent Moon is still below the horizon, so the sky will be darker, especially Sunday night.
The meteors should be easy to spot from between Mars and the giant red star Betelgeuse (Orion’s shoulder) high above the northeastern horizon.
Mars and Betelgeuse also form a triangle with Aldebaran, the giant red star that forms the eye of Taurus, the bull.
“Having the three red objects in a triangle is always a lot of fun,” says Dr. Hill.
So how many meteors will you be able to see?
While the Northern Hemisphere reports the Oronides as the best meteor shower of the year with between 10 and 40 meteors per hour, rates are much less prolific in the Southern Hemisphere.
Dr. Musgrave predicts that we can expect to see, on average, a meteor every four minutes.
“You won’t see a lot of them because the radiant never gets very high in Australia, but they’re quite nice,” he says.
If we’re lucky, though, there’s an outside chance that meteors could put on a special display, says Dr Hill.
There is evidence that the meteor stream is pushed by Jupiter’s gravity, causing them to become more active every 12 years.
“The last time that happened was in 2006/2007, when the number of meteors doubled,” he says.
The further north you are, the better.
Here is a table showing the average predicted rates for dark-sky locations at latitudes equivalent to some of Australia’s major cities and towns (rates in urban areas affected by light pollution will be lower).
Location
Friday October 21
Saturday October 22
Sunday October 22
Adelaide
10/hour
13/hr
14/hr
Brisbane
11/hour
15/hr
16/hr
Cairns
12/hour
17/hr
19/hr
Canberra
9/hour
13/hr
14/hr
Darwin
13/hr
18/hr
19/hr
Hobart
8/hr
11/hour
11/hour
Melbourne
9/hour
12/hour
13/hr
Perth
10/hour
14/hr
15/hr
Sydney
10/hour
13/hr
14/hr
If you missed this year’s Oronides, don’t despair. Australia’s best meteor shower, the Geminids, is just two months away.
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Oronid meteors are usually very bright and fast.
“They can often leave magnificent trains behind where the meteorite passes, but it persists for a second or two,” says Dr Hill.
You might even see a couple of slower meteors in the same area from different meteor showers known as the Southern and Northern Taurides.
You don’t need anything but your eyes, a nice dark place, and a lot of patience (even though we said one every four minutes, we didn’t mean literally every four minutes).
To catch meteors, you need to scan the sky, rather than fixating on a spot.
“Let your eyes move, for although the radiant is at the point where the meteors seem to originate, most of them begin to burn or shine away from this point.” says Dr. Musgrave.
But wait! That’s not all
If you have binoculars or a telescope, take a look at Mars while you wait (just be careful not to miss the meteors).
“Mars will be at opposition next month, so it’s continually brighter,” says Dr Musgrave.
If you look away from the meteor shower to the west, you’ll also see Jupiter, which recently reached opposition and made its closest approach to Earth in nearly 70 years.
“Jupiter looks so beautiful and bright right now,” says Dr Hill.
And don’t forget to take a closer look at the bright stars of Orion and Taurus, which also contains the beautiful Pleiades cluster, known as the seven sisters of indigenous astronomy, as well as Sirius, the brightest star of the constellation sky. of Canis Majoris.
“It’s such a rich area of the sky,” says Dr Hill.