We are gazing up at world's largest international dark sky reserve (4144sq km), only the fourth such reserve in the world. The Milky Way and the "Jewel Box" (a cluster 6000 light years away) are clearly visible to the naked eye. The only thing that could rain on this parade is heavy cloud or the moon.
"There's nothing worse than a full moon," says Josh, another guide.
This is a light-pollution-free zone and a full moon is the worst offender. No white light allowed, we are warned on our shuttle ride up the mountain. No cellphones, no iPads, no torches.
Nothing can interfere with the majesty of the skies. For around a couple of hours, the only source of light to guide our way over the lumpy ground around the telescopes, and each other, is a small red solar-charged torch, for each of us in our group of 22, to take home as a souvenir.
Our eyes adjust quickly to the darkness and the payback is immense. Even on a cloudy night, the clarity is at 60 per cent. The night we're there, at about 9pm, it's around 85 per cent clarity.
We can only just make out the small village of Tekapo (300m below, pop. 300). In solidarity with science and the star gazers at Mt John, the town planners ruled the street lights are capped and must point downwards.
Someone hands out hot chocolate to warm us up. Not that we need it, in our standard-issue Antarctic-grade jackets.
"I studied astronomy at the university of YouTube," Josh says. Astronomy, he says, is 90 per cent physics, and 10 per cent enjoyment. Josh was all about the fun, so took a detour around convention and ended up a DIY expert on the southern skies.
He is also endearingly unsentimental. Spoiler alert: A shooting star is just a rock from a star, randomly falling.
We got to Tekapo on day six of a nine-day journey. The day we left Auckland there was no sky. We were excited about new horizons, visiting towns with names both familiar and distant.
Our campervan is a perfect fit. We travel to 12 towns and wherever we look there are mountains — a vast reference point that's alluring and terrifying. The real joy of travelling by campervan is that we can stop wherever we like, and we do.
There were many just like us parked up at Tekapo. If viewed from space, our campsite would resemble a ribbon of shining white hardware. We set ourselves up for two days in what's grandiosely called The Front Row, which looks out over Lake Tekapo and layers of mountains.
The light here is blinding. The colours dance. The kids gather rocks and declare they've "totally, absolutely, probably" discovered crystals and pounamu. There are some brave souls swimming in the lake. Actually, they're standing waist deep and not moving. It's 7C in there and they are possibly in shock.
Some fool is showing off in a jetboat.
At the lake's edge a tourist is trying out a drone. It lifts into the sky, a weird white alien, and vanishes above the clouds. You can still hear it, though, up there somewhere, taking aerial shots of small colourful people, glancing skyward, waiting to see what it's captured.
Tekapo Springs
We'd just finished the hour-long walk up Mt John and jogged back down, before sinking into the natural spring baths that overlook Lake Tekapo and the Two Thumb Range. It's an eye-wateringly gorgeous setting and the perfect end to an epic road trip.
From the adults' pool, nicely warm at about 40C, we soak our travel-weary bodies and look out over the mountains and — nearer still — the kids playing in the slightly cooler baths.
We duck in for a steam, then a sauna, then into the plunge pool (8C) and jump back in the adults only pool. We repeat several times.
At the Glacial Day Spa. Chris gets a Moana massage, which includes oils and creams that are based on traditional plant-based Maori healing methods. I have a pedicure and am somehow convinced by Ruby, the therapist, that purple glitter is the business. We are at the springs during the shoulder season. The ice rink has just closed when we arrive, and the water slide hasn't quite opened.
Tekapo Springs won the innovation award in September.
Lessons
1. Everything is not . . . two and a half hours away. South Islanders seem to have a different concept of time and distance. We are often told "Oh, that's about two and a half hours away". Simply by looking at a map, we know this not to be true. But we get sucked into the narrative anyway and end up taking in the south-west, and up to Manapouri, rather than heading up the interior, which takes another day or so. But it's a delightful diversion. We regret nothing. There are few cars, and beautiful roads.
2. Try to make . . . each day's drive no longer than three hours so you can fully appreciate the stops and not feel as though you're relentlessly on the move.
3. Don't be afraid . . . about taking a road trip with smallish children in a small confined mobile play house over many days. On paper it sounds like hell. But it's up there as one of the best family holidays. Ever.
4. Unclench yourself . . . you are no longer in the Big Smoke. The roads in the south are straight and empty, by comparison. The space-to-people ratio is pleasing.
5. Stop at small towns ... even if you have to make Riverton from the Catlins by nightfall, make sure you stop along the way. We stopped at magnificent op shops, bought bargains and icecreams. Had conversations with locals.
6. Hot tips ... get pasta from Asta La Pasta at the Oamaru markets. While you're there, get meat from Danny the butcher.
Get wine from Oamaru New World — bargains to be had. Collect cockles from Papatowai, in the Catlins and steam in butter and garlic. Serve with a Central Otago riesling. Get blue cod and chips at Bluff. Walk along the beach at Monkey Bay, on the south-west coast. Take dear friends and a sense of adventure.
Cosmic couples
Could there be a more romantic notion than star gazing with your loved one, while sipping bubbles in the warmth and comfort of a hot pool? Tekapo Springs' star-gazing tours enable guests to enjoy the after-hours soak (from 9.30pm onwards), watching the moon and stars above, while a qualified guide points out the brightest features of the night sky.
Guests will also be able to experience a close encounter, looking through two new 9.25 aperture Celestron telescopes sitting on the patio outside the complex's Tahr Bar & Cafe.
Jucy Casa Plus
This Italian-made mobile home sleeps up to six comfortably and has mod-cons, including toilet, shower, a flash kitchen, outdoor furniture and heaps of space for luggage.
There are endless cute compartments, like a mobile play house.There's a decent kitchen with gas hobs, a reasonable sized fridge (though you'd do well to take a chilly bin in the summer).
The kids can watch movies on the small TV, and there are well-designed reading lights.
The best seats in the house are up the front. The back bench seats are around a table, which folds away at night to make another double bed. The kids play cards when they're not being instructed to "look at those mountains, guys!"
