General navigation using the sun, moon and stars is actually a pretty simple process provided that you understand some basic principles.
Such as the fact that the sun rises in the east and sets in the west and thus, if you are in the northern hemisphere, the sun is located due south at noon while, if you are in the southern hemisphere, it’s due north of you at noon.
Also, by noting where the sun rises on your horizon and which direction it is traveling, you can determine the cardinal directions of north, south, east and west. Therefore, because the moon and the constellations also follow approximately the same path, you can use them for the same purpose when navigating at night. But, because Earth’s terrain often forces you to travel a less-than-direct path and, because our celestial bodies continue to move across the sky during the course of the day and night, using them to navigate can be a little tricky. However, there are a few techniques that can make doing so significantly easier.
For instance, when using the sun as a navigational aid to keep yourself on course, you should note the position of your shadow because if you are in the northern hemisphere traveling parallel to the sun’s path, you shadow will always be on your right if you are traveling west and, if you are traveling east, the opposite will be true. However, you should also note that the position of your shadow will change slightly as the position of the sun changes and thus, if you are traveling west, it will be in front of you in the morning and behind you in the afternoon and the opposite will be true if you are traveling east.
Also, provided that you are in the northern hemisphere traveling perpendicular to the sun’s path, if you are traveling north, your shadow will always be in front of you and, if you are traveling south, it will always be behind you. In addition, if you are traveling north or south, your shadow will be longer in the morning and afternoon hours than it is at high noon because the sun’s position is higher in the sky at noon. Therefore, the length of your shadow can also be used as primitive method of keeping track of the time.
Fortunately for us, the moon also follows approximately the same path as the sun and therefore, we can also use the moonrise and moonset to determine the cardinal directions. However, most nights the moon does not reflect enough light from the sun to provide us with a distinct shadow.
But, even though we may or may not have a reliable shadow by moonlight, the moon still serves as a reliable navigational aid by first enabling us to determine in which direction lies north, south, east and west and then by providing us the same guidance as the sun by remaining on our right or left sides when traveling east or west (depending on which hemisphere you are in) and by remaining either in front of us or behind us when traveling north or south (again, depending on which hemisphere you are in).
Last, even on nights when there is no moon visible, we can still use the constellations of the Big Dipper and the Little Dipper to find true north because the northern axis of the Earth just happens to point to one of the brightest star in our night skies which we call Polaris or, the North Star. (It’s the brightest star in the constellation Ursa Minor, also known as the Little Dipper.) Therefore, when you are facing the North Star, you are also facing true north.
So, in order to locate the North Star, first locate the Big Dipper in the northern sky and then locate the two stars that form the outer edge of the cup (the two stars located farthest from the handle). Next, draw an imaginary line straight through the two stars of the cup’s edge across the sky to the last star in the handle of the Little Dipper. Notice that that star is noticeably brighter than all of the other stars around it. You just successfully located the North Star. When you know that you are facing true north,
So, in order to locate the North Star, first locate the Big Dipper in the northern sky and then locate the two stars that form the outer edge of the cup (the two stars located farthest from the handle). Next, draw an imaginary line straight through the two stars of the cup’s edge across the sky to the last star in the handle of the Little Dipper. Notice that that star is noticeably brighter than all of the other stars around it. You just successfully located the North Star. When you know that you are facing true north, south will be located behind you, west will be on your left, and east will be on your right.
So, even though a far better solution is to carry a GPS device, celestial navigation is a viable method of determining a direction of travel – especially if your GPS is misplaced or its batteries drained.
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