Where many other meteor showers are often over-hyped , the Geminids are the real deal: far and away the best shower of the year, peaking on December 14-15 in Australia and Aotearoa New Zealand.
Author
- Jonti Horner
Professor (Astrophysics), University of Southern Queensland
The Geminids - dust and debris left behind by the rock comet Phaethon - put on a fantastic display every year, but 2025 promises to be extra special because the Moon will be out of the way, giving us perfectly dark skies.
So where and when should you look?
Meteors that radiate from the constellation Gemini
The key thing for working out the visibility of a meteor shower is its "radiant", the single point in the sky from which the meteors seemingly originate. For the Geminids, at their peak, that point lies within the constellation Gemini, near the bright star Castor (α Geminorum).
The radiant is a result of perspective - the dust that causes a given meteor shower is all travelling in the same direction towards Earth, just like the lines in the drawing below.
The higher the radiant is in the sky, the more meteors you will see. When the radiant is below the horizon, you won't see any meteors from that shower because they are hitting the other side of the planet.
What time should I look?
The absolute best time to observe is when the radiant is at its highest in the sky, called "culmination", which happens around 2am or 3am local time on December 15. But any time between midnight through dawn will be a great time to watch the meteor shower in Australia and New Zealand.
The time at which the Geminid radiant rises varies depending on your latitude. The farther south you live, the later the radiant will rise. And the farther north you live, the higher in the sky the radiant will reach, increasing the number of meteors you will see per hour.
The more light-polluted your skies, the fewer meteors you'll see. Fortunately, the Geminids often produce many bright meteors so it's worth looking even from inner city locations. Just remember the rates you see will be markedly worse than if you were camping somewhere dark in the countryside.
If the forecast is cloudy for the night of the Geminid maximum, the nights of December 13 and 15 will still offer a decent display, although not as spectacular.
Where should I look?
The Geminids can appear in any part of the night sky, but the best place to look with the unaided eye is usually around 45 degrees to the left or right of the radiant (whichever direction is a darker sky for you).
The easiest way to work this out is to find the constellation Orion, and look so that Orion is about 45 degrees from the centre of your vision.
I'd recommend spending at least an hour out beneath the stars when looking for Geminids, to give your eyes enough time to adapt to the darkness. Don't look at your phone or any other bright lights during this time. Instead, take some blankets and pillows and lie down.
Ideally, you want to be resting so that the centre of your vision is about 45 degrees above the horizon. Then lie back, and enjoy the show. Remember that meteors come in randomly - you might wait ten minutes and see nothing, then three come along all at once.
Why do meteors look different in photos?
In the days after the Geminid peak, you'll doubtless see lots of spectacular images on social media. But photos showing dozens of meteors against the background stars are composites of many photographs taken over a period of several hours.
Keen photographers will often set up their cameras pointing at the northern sky, take a lengthy series of exposures, then pick those with meteors in them and stack them together to make a composite image.
If you want to try this yourself, here are a couple of useful tips.
First, to avoid any star trails on your individual images, follow the rule of 500 . Find out the focal length of your lens (common wide-angle lenses have focal lengths of 14 to 35mm), and set your exposure time to be less than 500 divided by the focal length of your lens. For example, if you're using a 50mm lens, you'd have to keep your exposures under 10 seconds.
Next, set the lens focal ratio, or f-number , to be as small as possible. This will ensure the lens is wide open, allowing it to gather as much light as it can during each image.
Finally, set the ISO of your camera to be relatively high , choosing a number of at least 1,600. The higher you set the ISO, the more sensitive your camera will be to light, and the fainter the objects visible in the dark sky images. However, be warned that setting the ISO too high can make your images grainy.
Once all that is done, set up your camera with the field of view you want to image, take a timelapse of the sky, and leave your camera running while you watch the skies. Hopefully over the course of an hour or two under the stars you might just capture some spectacular shots of debris bits burning up high overhead.
Jonti Horner does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.
