New Zealand nights and Southern Sky stargazing

A trip to New Zealand for anyone from the northern hemisphere should include the treat on a clear night sky of a little southern hemisphere star gazing. If you have the good fortune of being away from an urban center, which is easy on the south island, and catch a clear night, be sure to take time to look up to the night sky.

Even if you’re only mildly interested in the night sky, the southern sky is completely different, and has some really cool features. It is another of the mildly unsettling ‘opposites’ that a traveler from the U.S. will encounter, such as driving on the left, or realizing that a southern wind is a cold wind while a northern tropical wind is pleasantly warming.

Back to the sky: There is no star akin to our “North Star”, or “Polaris.” This important northern hemisphere star, easily located if you can find the big dipper, is almost directly over the earth’s northern axis. So if you can find the North Star, you can identify true north; it’s been a pillar of northern hemisphere navigation for thousands of years. The southern hemisphere has no such fixture; instead, it has the iconic Southern Cross. The Southern Cross is a beautiful and easy-to-locate constellation, but it is only generally south; it is not a navigable precise point, it rotates. But you’re on vacation and have a GPS, so who cares? The Southern Cross is distinctive and has some of the brightest stars in the night sky, so it’s visible early or in lightly hazy weather too. The Cross appears on both New Zealand’s and Australia’s flags, so you know for the folks down under, it’s a cultural fixture.

The next really cool object is that our nearest neighbor, Alpha Centauri; this is one of the two pointer stars to the Southern Cross. It is also very bright (after all, it’s only about 4 light years away). Aside from being bright and close, Alpha Centauri is actually a binary star: this means it is paired with another star, and the two rotate around each other in a seemingly perpetual figure skaters’ dance (and are known as A and B). From my childhood, I recall the “Lost in Space’s original mission was to go to Alpha Centauri as our nearest neighbor, and since then have felt cheated that I couldn’t ever see this closest neighbor. It’s easy in New Zealand.

Another well known astronomical fixture that any hobby astronomer has read about and seen pictures of are the two Magellanic Clouds, two dwarf galaxies, rotating closely to our own Milky Way. They appear as small clusters of stars; an early name for these was “The Sheep”, by the Persian Astronomer Al Sufi in the tenth century. They are the brightest objects beyond our own Milky Way, and are classified as dwarf galaxies. They are roughly 7000 light years and 14,000 light years across; our Milky Way is about 150,000 light years across, as a point of comparison. The Large Magellanic Cloud was the source of a supernova in 1987, so you had to be in the southern Hemisphere to see that.

Interestingly, the Zodiac , which includes constellations that early Greek and later Roman navigators watched and named, are visible in the southern hemisphere too. The reason is that they are closer to the earth’s equator, and thus close to the horizon for both northern and southern viewers. The seasonal appearances are caused by the earth’s tilting, making constellations appear in the night sky at different times of the year.

Each of these can be appreciated without the benefit of a telescope, or even binoculars. However, a visit to Lake Tekapo (only a few hours southwest of Christchurch) can get you a lot more. Visit the Earth and Sky Astronomy tours for a visit to the Mt John Observatory or a separate view on a hill top (complete with serious telescopes, too). Either will expose you to some of the many unique southern viewed galaxies, including some of the ones described here by a far more dedicated amateur astronomer than I. It’s a real treat, even if your trip isn’t about astronomy.