Aotearoa/New Zealand's heritage seems to be wedded to our night sky, from the celestial navigation used by those who came ashore in the first waka, to Captain James Cook and his astronomer Charles Green's observations of the transits of Venus and Mercury here two and a half centuries ago. Do you think this grassroots connection has been lost over time?

Yes. We don't need astronomy to help guide our day-to-day lives anymore, or to help us navigate. Outside science, the night sky has become a hobby for some and an occasional rural curiosity for the rest of us. As cities have become more illuminated we've lost our view of the stars, and I think with that we've lost a really important connection with the environment, animals, and the rest of humanity as a result.

Once you consider that the night sky and its regular yearly pattern is the only thing in the natural world that won't change in our lifetimes, and that this experience is the same for everyone on the planet, you really start to get a sense of it being a roof over our shared humanity. Knowing a bit about astronomy and the night sky is a powerful resource for culture, science, history, art, health, zoology and sheer beauty. But there is a growing dark-sky movement that has recognised what is being lost, and it is awesome to see the recent resurgence in Māori astronomy, sparked by people like the University of Waikato's Dr Rangi Matamua, who puts in a huge amount of effort sharing his tatai arorangi knowledge via social media and lectures. We have some of the darkest skies in the world and I would love to see more New Zealanders spend more time admiring them, which helps lead to their preservation from light pollution.

Naomi Arnold author of the book Southern Nights the story of New Zealand's night sky from the Southern Lights to the Milky Way. Photo / Supplied
Naomi Arnold author of the book Southern Nights the story of New Zealand's night sky from the Southern Lights to the Milky Way. Photo / Supplied

On that resurgence: we're seeing more people celebrating Matariki each winter, with some suggesting the Māori New Year be observed as a public holiday, or at least given more prominence than other occasions like Guy Fawkes. Is that something you'd like to see?


Personally, yes, but it depends on how Māori feel about their traditional astronomical knowledge being used in that way of course. Some star lore is for tohunga only, but there are plenty of stories that local iwi use for general public consumption in their community celebrations.

Overall, it can't be a bad thing to have more New Zealanders learning about and respecting the vast store of astronomical knowledge Māori have and how it helped them survive in early New Zealand. It's important for New Zealanders to understand how so much of that knowledge was lost through forced cultural assimilation and early Pākehā's imposition of Christianity over such "pagan" practices. Matariki is also great for introducing kids to space.

Compared with the Northern night sky, what's above us has only been explored relatively recently. Why is this?

New Zealand was inhabited much later than the rest of the world, and much of the southern skies were unknown to Europe until explorers began to venture down here, map them, and publish.

Amateur astronomy has always been in respectable health in New Zealand and astronomers have made important contributions to global knowledge, but in terms of professional astronomical scientific research there simply weren't as many professional observatories, despite New Zealand's position on the planet being an important point in continuous global observation. In 1960, for example, there were only 10 observatories set up in the entire southern hemisphere, compared to 88 in the northern hemisphere, and none were in a site carefully chosen for the quality of their skies.

Eventually, efforts were made to address this including setting up the University of Canterbury Mount John Observatory in Tekapo, in collaboration with a university in the United States.

At the last check, light pollution levels above New Zealand weren't too bad. Based on land area, about three quarters of the North Island and 93 per cent of the South Island had night skies that were either pristine or degraded only near the horizon. Still, is there a danger we could lose this?

Yes, wherever people go, they bring light. Humans love extending daytime hours with artificial light. I think dark-sky preservation should be enshrined in law and building codes by using appropriate outdoor lighting for roading, homes, and commerce. This includes colour temperature — the warmer the better, for animal and human circadian health — luminosity, light placement, shielding, and considering if a light is needed at all.


A final question: what are your favourite things about our night sky?

Overall, the fact that it is always there. It's so rewarding to go out on a dark night and lie down with a blanket and spend a few minutes sinking into wonder, considering that you're a passenger on a planet whipping through space, and that each of those bright white dots is a little sun or planet, and that the more you learn, the more questions you have, and then you're galvanised to find out more. Everyone has felt at least moments of this at times.

It's refreshing to consider the unimportance of your life and think about how our ancestors used the sky to live their lives, and what people on the other side of the world are doing right now. Last night when we went out with the telescope, most of the planets had dipped below the horizon and it's simply just a cool thing to think about where they were right then in relation to yourself and when we could see them again, turning the Earth in your head like a Rubik's cube, looking forward to Scorpius and the galactic core of the Milky Way coming back into view as winter comes on. It's like a brain and perspective reset.

Southern Nights, by Naomi Arnold, (HarperCollins, $65).