It’s that time of year when many of you urbanites head out of the city to go tramping or camping. One thing you’ll almost certainly notice, as you leave the bright lights behind, is the stunning vista of the night sky. Auckland isn’t quite LA or Tokyo, where locals can go much of their lives without ever seeing the stars, but the sight of an unpolluted night sky might still be revelation.
Even for us country folks who are used to a star-strewn night sky, though, knowing how to navigate the celestial display is fast dying out. As a young astronomy nerd, I learned to recognise many of the major constellations and identify the planets by sight. I find I’m very much the exception, though.
Here’s a short guide to the basics of navigating the southern night sky.
The best way to orient yourself when looking at the night sky is to work out where south is. First, find the Southern Cross (tip: in summer it is low to the horizon at sunset), then draw an imaginary line about three-and-a-half times up the length of the major axis of the cross, in the same direction as the major axis – where this imaginary line ends is approximately due south.
This is something that was once essential knowledge to not just sailors, but anyone trying to find their way around unfamiliar territory at night. Given how many people wind up losing themselves here in Tasmania, it might come in handy.
The two bright stars next to the Southern Cross are the “pointers” or Alpha and Beta Centauri. Alpha Centauri is the outer star and is a triplet star system, containing the nearest star to us outside our solar system, Proxima Centauri. It takes light 4.25 years to get from this star to Earth.
Those two stars are not, in fact, part of the Southern Cross. As their name suggests, they belong to the Centaur constellation. To picture the Centaur, if the Southern Cross is pointing down, the Pointers form part of his foreleg. With a little imagination, you’ll soon see a gigantic centaur galloping across the sky, hunting the nearby wolf, or Lupus constellation.
It also helps if you envisage the Cross as, well, the Centaur’s naughty bits. I’m not kidding: they’re in exactly the right spot. Guess it’s lucky we didn’t end up with the ‘Horse Dick’ constellation to navigate by.
Leaving the Centaur, there’s another, far more famous hunter in the sky: Orion. More familiar to us in the south (where he strides the sky upside-down) as ‘the Saucepan’. At this time of year, Orion is in the northern sky just after sunset.
Switch your attention to the north and you’ll see three bright stars in a row – these form the belt of Orion, or the base of the saucepan. There are three nearby bright stars at about a 45-degree angle above the belt – this is Orion’s Sword (or the handle of the saucepan). The middle “star” looks fuzzy because it is actually a nebula containing newly forming stars.
If you follow the line of the belt to the right, you’ll see the brightest star in the southern sky, Sirius, in the constellation of Canis Major (the large dog – which is upside down in the southern hemisphere). Continue to the right and you’ll find the star Canopus – the second-brightest star in the night sky.
Leaving the stars, let’s turn to the planets. The three easiest planets to find are Jupiter, Venus, Mars and Saturn.
The easiest planet to find in the sky right now is Venus – it’s just above the setting sun and will be the first and brightest “star” to appear in the night sky. I look at this planet every night – sometimes it is near the setting crescent moon, which provides a beautiful sight.
Saturn is slightly above and to the right of Venus – not quite as bright but easily visible as the first bright “star” near Venus. Next, we can find Jupiter: head back to Orion and follow the belt to the left – you’ll get to a bright red star which is Aldebaran in the constellation of Taurus. Just near Aldebaran is a very bright “star” – this is the planet Jupiter.
Red Aldebaran is Taurus’ ‘eye’. Taurus is easy to identify by the distinctive V of his horns. Slightly lower and to the left of Aldebaran is another famous constellation: the Pleiades. These ‘Seven Sisters’ are depicted as being carried on Taurus’ shoulder (remember, the bull is also ‘upside-down’ to us).
If you’re unsure which planet is which, Mars is, famously, red. Venus is extremely bright and pure white. Jupiter is slightly less bright and an off-white colour. Saturn is duller than both and distinctly yellow.
Heading right out into the universe, we can see several galaxies. Starting with, of course, our own: the Milky Way.
Our own Milky Way galaxy stretches across the sky. It’s a spiral galaxy which is approximately shaped like two dinner plates placed face-side together. We are looking edge-on to the galaxy so it appears snake-like across the sky. The dark patches are thick dust clouds that are blocking out the light of the background stars […]
The other two visible galaxies are the Magellanic Clouds. The Large Magellanic Cloud is about halfway up the sky above the Southern Cross, to the right of Canopus – and looks like a faint cloud. The Small Magellanic Cloud is to the right of the Large Magellanic Cloud. These are dwarf galaxies that are interacting with the Milky Way, eventually to merge with our own galaxy.
I’ve known people to mistake the Magellanic Cloud for actual wisps of cloud. Except in the darkest skies, they’re very faint, so it’s sometimes easier to see them by looking slightly to the side and seeing them ‘from the corner of your eye’.
Other things to look out for are meteors and auroras. With a bit of patience, you’re guaranteed to see at least a meteor. Watch the sky for 10 minutes or more and you should see a shooting star streak across the sky.
For the last few months, the Sun has been particularly active, so aurora sightings have been more frequent – and spectacular – than usual. The Solar Maximum is expected to continue through 2025. If you’re in the top half of the North Island, you’re unlikely to see one. Most likely you’ll see a dull red glow on the southern horizon. In the South Island, though, you’ve got a chance of a real celestial treat.
The colours of an aurora are best seen through photos from a modern phone – especially if your phone has night mode. But you can see a strong aurora with your eyes if it’s dark with a good view of the southern sky. The telltale signs are “beams” of light coming down from the sky – they move around the sky on a timescale of a few minutes, and if you are lucky you’ll see the faint pink and greens. A great trick is to take a photo every 30 seconds or so and then flick through the sequence of photos to see the aurora swirling across the sky.
If you’re out at night, just keep an eye to the south – use the Southern Cross, remember! If it’s fully dark and the southern sky is glowing, then that’s an aurora. Enjoy.
