Finding true North using Ursa Major/Minor..

Jranger

Senior Member
I've read up on how to find the North Star using both, but I'm unclear on how this determines true North? The brightest star in Ursa Minor's handle is Polaris, but depending on your vantage point how do you line this up to point North?
 

bigox911

Senior Member
Polaris just is north...it doesn't change no matter what your vantage point is :huh:
 

Jranger

Senior Member
Polaris just is north...it doesn't change no matter what your vantage point is :huh:

ok... So if I line up with Polaris I'm facing North no matter where I am in the Northern Hemisphere...? Crisis averted...:D
 

jason4445

Senior Member
There is a difference between true north - where the north pole is, and magnetic north - where the compass needle points. True north and magnetic north are approximately 590 miles apart, but that changes from time to time. Just do a search on true north and magnetic north to learn more.
 

Oldstick

Senior Member
Not sure what constellation the north star is in, but I was always told to find the Big Dipper. Then the two stars forming the front "pouring" edge of the dipper make a line which points over to the North Star. Just start at the edge of the dipper and follow up along that line to the brightest looking star you come to.

The north axis that the Earth rotates on is pointing almost directly at the North Star. Therefore it never appears to change position in the sky. All the other stars appear to rotate around this star during the night.

If you are looking at the North Star you are facing North.
 
This discussion brings back memories of my Geodesy class at Troy State. If I remember right Polaris when looked at through a total station actually appears to wobble and we used an atomic clock/radio and GMT time to calc the wobble and some how come up with north. Of course that was several years ago and only performed that procedure once so I may be just muddying the waters.

I think the North Star is in the Casio-Paea(sp?) constellation

There are also 3 Norths True North, Magnetic North and Grid North. Magnetic North varies from year to year and location based on the earths magnetic fields changing. Also local attraction such as reading a compass near a truck or metal objects can affect the reading. Areas with iron ore deposits also affect compass readings. Grid North is based on a flattened projection of the earth, because the earth is round and subject to distortions due to convergence over long distances and flattening at the earths poles.

Hope this helps I studied this in depth in my Geomatics program but like I said that was years ago.
 

Jranger

Senior Member
Well... this began as my son and I were discussing what he should and should not do in the event he becomes lost. Mainly I was just trying to instill in him the idea that he needs to be aware of his surroundings. Many people don't pay attention when they are taken somewhere as to where they are actually going and any significant landmarks along the way. I was trying to have him become more confident (and I in him) when out in the woods that if something happened to me while we are hunting or whatever that he would be alright.

That topic sorta spawned the being able to tell where North is based on looking at the stars. Honestly, I'm still having trouble finding the little dipper @ night. From what I have read, Polaris isn't the brightest star in the sky so it's not jumping out at me. I need to check out google earth tonight and take a look again with some reference to what Ursa minor looks like...:O
 

rjcruiser

Senior Member
Like posted above, find the big dipper. Then follow the two stars that make up the far end of the pan. those two will point to the north star....which is also the handle star of the little dipper.

Here's a simple pic to help. Notice that's me with my wife and two kids at the bottom right :D
 

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Oldstick

Senior Member
Good idea with the pictorial.

Go out at several different times of the night and look where you already know north is and kind of practice seeing what the Big Dipper Looks like. Polaris will always be at the same elevation in the sky if your location (i.e. latitude) is the same.

During the night the Big Dipper will appear to be circling around Polaris. But those two stars will alway stay oriented towards it.
 

Swamprat

Swamprat
Well... this began as my son and I were discussing what he should and should not do in the event he becomes lost. Mainly I was just trying to instill in him the idea that he needs to be aware of his surroundings. Many people don't pay attention when they are taken somewhere as to where they are actually going and any significant landmarks along the way. I was trying to have him become more confident (and I in him) when out in the woods that if something happened to me while we are hunting or whatever that he would be alright.

You are correct in your teaching. But first and foremost is for him to be adept with a compass. A cloudy night will prevent him or anybody from using the stars for orientation. A compass will work every time if used properly.

In flat country landmarks are basically useless because the tree canopy prevents you from seeing or applying them. We have relied on radio towers for orientation more than anything.
 

Jranger

Senior Member
You are correct in your teaching. But first and foremost is for him to be adept with a compass. A cloudy night will prevent him or anybody from using the stars for orientation. A compass will work every time if used properly.

In flat country landmarks are basically useless because the tree canopy prevents you from seeing or applying them. We have relied on radio towers for orientation more than anything.

Very true... my next effort will be a course offered up at Creekside range. I need to look at the details again, but last year they had the course several times. They give you a short course on navigation with a compass, then drop you off on at night. You have to hit certain way points on your way to the final destination. The course is a father/son or two person course. Looks interesting. Thanks for all the help guys...
 
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