Without clouds, about 6,000 stars are visible in the night sky, from anywhere on Earth. This number is lower in areas of heavy light pollution, but for the most of human history, this is what we had to look up to. In earlier times, there were many ideas as to what the stars were. The Greeks saw constellations, who were sentient, divine beings, awarded with the place among the stars, for some great deed done long ago. To the Paiute tribe, who lived in the Great Basin of North America, stars were the children of the Father Sun and the Mother Moon, eaten everyday by the light of the Sun, and nursed back to life by the love of the Moon.
In Chinese mythology, some stars represented actual people. One is Jīn Yú – “the girl who weaves the clouds”. And another is Nu Lang – “the herdsman, who cares for the cattle of the Heavens”. The two were in love, so the Gods places them on either side of the Milky Way, to make sure, they were never distracted from their duties. Only once a year, on the 7th day of the 7th month, the two lovers are allowed to meet, when the birds in the sky will form a bridge across the Milky Way. To the Yakut tribe of Siberia, the stars are crystal lenses, used by the Gods to watch the Earth. And for the Turk people of central Asia, the sky was one big tent, and the stars were nothing more, than small rips in it. Of course, we know now that all of these stories are wrong. And in fact, stars are giant gas clouds, glowing from the process of nuclear fusion, billions of miles away. But of these ancient understandings of the stars, one remains true to this day. And no, it isn’t Zodiac readings – but navigation. Ancient travelers, and modern sailors, and pilots alike, would use the stars, to voyage through their lands, and to discover new ones. So, how did they do it? How do you navigate using the stars?
Well first, a quick look at some time-lapse photography, will show, that the stars are not static in our skies. But instead, they streak across the sky, as the Earth revolves. Using a moving star as a reference point is problematic, especially for long journeys, so you can’t just pick any star in they sky, and follow in its direction. The same problem is present for the Sun and Moon for navigation, as they will move across the sky in a similar way. And while many think, they may be able to use the Sun, at the very least to rise in the East and set in the West, due to the Earth’s seasonal tilts, it’s rare, that the Sun ever rises in true East, or sets in true West. Only on the equinoxes, at the equator, does this occur – just twice a year. So, what’s needed is a reference point, that no mater the year, month, week or day, will always lead you in the same direction. One last thing before we get started, is the stars used for navigation vary, depending on which hemisphere you’re in, north or south; as the stars in the northern hemisphere can’t be seen from the southern hemisphere, and the other way around. So – knowing that, let’s get into it.
First, we’ll start in the northern hemisphere, and here, we’ll find perhaps the most well-known star for navigation – Polaris, the North Star. By random chance, Polaris sits virtually on top of true North, just a fraction of a degree off. And because of this, it barely moves in the sky, while all the other stars spin around it. This can be seen best in long-exposure photographs, where all the moving stars make long streaks through the sky, but at the center is Polaris, hardly moved at all. Finding the North Star is fairly simple, too. It’s the brightest star in the constellation Ursa minor, the Little Dipper, or the Little Bear. Polaris is the last star in the handle. If you’re having trouble spotting it, you can look for Ursa major, the Big Dipper, or the Big Bear, which I find much easier to spot. Once you found the Big Dipper, you can use its end stars, called the Dubhe and Merak, and follow the path they make, straight to Polaris. If clouds are covering Polaris, but not the Big Dipper, know, that Polaris lays roughly 5 lengths of the distance between Dubhe and Merak away. Also be aware, that while Polaris stays relatively still, the Big Dipper, like the rest of the stars, will move, and sometimes may be covered by objects on the horizon, like mountains or trees. So it’s best to look for Polaris on high ground.
Okay, so what about for going South? Can we just find the North Star, and sail in the opposite direction? Well, no. Without a point to aim your ship at, there’s no real way to ensure you’re sailing in the right direction. Instead, you’ll need to find another well-known constellation, Orion. And if that just looks like a bunch of random stars, don’t worry. All you need to know is his belt. These three close stars in a straight line: Alnitak, Alnilam, and Mintaka. Mintaka comes up again later, so try to remember it. But from here, you’ll need to find what’s called Orion’s sword, which hangs from his belt. It’s these three stars here, made from a dim star, a fuzzy star, and a bright star. That “fuzzy star” isn’t actually a star, but a huge gas cloud called the Orion nebula, where new stars are actually being made. If you follow the direction of this sword down to the horizon, this point should lead south. This gets a little inaccurate, when the constellation is lower in the sky, but should still bring you south. Okay, now we’re in the southern hemisphere, and this is where things start getting a little tough. But considering most of the Earth’s oceans are in the southern hemisphere, it’s still very much worth learning.
Here, we’ll find probably the second most popular method of using stars for directions, right after Polaris. If you’re Australian, Kiwi, Papua-New Guinean, Brazilian, or Samoan, you’re likely familiar with it already. And that’s the Southern Cross, more officially known as Crux. It can be seen as a cross, with an extra blemish star right here. Some may find this one a bit harder to find in the sky, as just about any 4 stars can make a cross in the sky. But there’s a way to help you find the right one. To the side of the Crux, there will always be two bright stars, sometimes easier to spot than the Crux itself. These are called the Pointer Stars, and you’ll need them again later. The Pointer Stars always point towards the Crux, and can confirm for you, if you are unsure, that you are in fact using the proper stars. After you’ve located the Crux, and its pointers, you’re going to need to do some more line-drawing in your head. Say your sky looks like this. Using the top and bottom stars of the Crux, draw a line out from the bottom of the Cross. Then, from the two Pointer Stars, draw a line out that is perpendicular to them, going in the same direction, as the line from the Cross. Where these two lines meet, is South. So just draw a line straight down to the horizon from there, and you should be good. Again: this is not 100%, absolutely, perfect South, but within a degree or so, and it’s as perfect as things get. Unfortunately, there’s no good way of finding North in the southern hemisphere, as Polaris is blocked by… well, the Earth.
But there are a few more tricks, that you can use in either hemisphere, depending on what time of year it is. If you’re near the equator – or the celestial equator, I should say, and you need to know East and West, you’ll again have to find Orion’s belt. Particularly, the leading star, meaning the first one that will rise above the horizon. This star is called Mintaka, if you remember. And the point on the horizon, where it rises, is always true East. And the point on the horizon, where it sets, is always true West. And then there’s one more easy trick, no matter where you are on Earth. First, take two sticks and plant them in the ground, roughly a yard or a meter apart. Then, pick a star in the sky, and adjust yourself, so that the stakes align and line up with the star. It helps to pick a bright star, that’s easy to keep track of. Then all you need to do, is wait for the star to move out of alignment with the two sticks. Depending on which way it moved, you’ll know one or two details about the way you face. If the star rose, you’re facing East. If it sank, the West. If it moved to the left, you’re facing North. And if it went to the right, you’re facing South. If it rose diagonally to the left, then you’re facing North-West, and etc. Of course, there are many more ways to use the stars, but I think we’re good for now. I hope you learned something useful.