Celestial Navigation …why the Navy is using it again…and why you should too…

Celestial Navigation Header

Just recently, the US Naval Academy in Annapolis, Maryland had announced that it was planning on reinstating instruction in celestial navigation. It hadn’t taught this subject since 1998.1

Why the change of heart?

First one needs to go back to see why they discontinued teaching it to begin with. By 1998, at least a dozen Global Positioning System satellites had been launched to continually circle the Earth, providing GPS receivers with latitude and longitude coordinates more accurate than any other sort of navigation could previously. By that time, celestial navigation, which had been around since ancient times, was dubbed outdated and unnecessary.  Computers were (and are) the answer to everything, right?

Well, many of you reading this by now can see the flaw in that logic. The problem is that computers are not the answer to everything. No doubt, they do magnificent things, but computers are not infallible. They are vulnerable to hacks, software flaws, hardware failures, etc. So why would anyone depend solely on one system, namely the GPS system, to work 100% of the time without fail?

If anyone believes that the Global Positioning System is beyond the reach of a hacker, I suggest one should think again. Any potential enemy would know that taking out the GPS satellites would be a prime method to handicapping the nation. It would be naive to think that there are not some out there who are making it a goal to do so to achieve an advantage. This seems to be the primary reason why the Navy is returning to celestial navigation…because one should always have a back-up plan in case one’s primary methods should fail.2 Besides hacking attempts, there are other scenarios which could cripple the GPS network as well. Solar flares could potentially disable satellites.3 Also, normal equipment failures are a factor. In fact, in 2009, a federal watchdog agency raised this as a concern when suggesting that the Global Positioning System was vulnerable due to the aging of its satellites, and due to the budget concerns of maintaining and replacing them.4

Now, I’m not suggesting that the Global Positioning System will fail anytime soon, but I am pointing out that it is a possibility…and in the spirit of preparedness, just as was said before, one should always have a back-up plan.

Which brings us back to celestial navigation…

This is an example of a sextant, which is an instrument used in celestial navigation.

Celestial navigation has been around for ages. It has guided travelers from ancient civilizations, it has led renaissance explorers in sailing the seas, and it has even helped Apollo astronauts navigate when they had other systems fail. It is the directional finding method which uses angular measurements between the sun, the moon, the stars, and the horizon in order to pinpoint one’s place on the planet. With such measurements, and a knowledge of which celestial bodies appear in the sky at different times, one can compute his or her approximate coordinates. The accuracy is not as definitive as it would be using GPS, but one can calculate his or her position with a stunning accuracy of within a few miles…all with just reading the stars, and all without computers or electricity. The tool with which one typically uses to assist in celestial navigation is called a sextant. It is an instrument which has a frame which is about 1/6 of a sector of a circle, and has attached to it a couple of mirrors, a telescope, and a scale for measuring angles. A good infographic for explaining the parts and the use of a sextant is found here.

Besides a sextant, another lightweight, inexpensive tool that one could use to aid in celestial navigation is called a planisphere. A planisphere is a rotating map of the sky. If one had knowledge of the stars, one could easily use one like a compass. To use one, all one would need to do is to shift the planisphere based on the date and the time, and a current map of the sky would then be presented. In fact, with a good knowledge of the stars, one could also use a planisphere as an accurate timekeeper as well. I have a few of these, and I can attest that they are definitely useful for both timekeeping and navigation.

There are other methods of celestial navigation as well. However, every method has in common the need for one thing: a familiarity with the stars, the sky, and the constellations. Such knowledge is a very worthy survival skill, and one could begin with something as basic as finding the North or South Pole.

As stated before, one should always have a back-up plan. Sole dependence upon one system which could potentially fail just sets anyone up for a possible disaster. While you may have never considered adding celestial navigation skills to your preps before, if direction finding is a part of your preparedness plans, you may want to consider doing so. If the Navy is using it again, why shouldn’t you?


  1. http://www.military.com/daily-news/2015/10/14/celestial-navigation-returns-to-naval-academy.html
  2. http://www.telegraph.co.uk/news/worldnews/northamerica/usa/11931403/US-navy-returns-to-celestial-navigation-amid-fears-of-computer-hack.html
  3. http://news.cornell.edu/stories/2006/09/solar-flares-could-seriously-disrupt-gps-receivers
  4. http://www.gao.gov/products/GAO-09-670T


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