Position Of The North Star.

[leigh47]

Is the north star a star in our milky way galaxy? If so where abouts is it in relation to our solar system and planet earth. (Don't exactly know how one can answer this without a picture representation of the milky way) I am interested to know how long the North star will apear "North" when viewed from earth.

[argorstran]

Yes the North Star is in the Milky Way galaxy

[bibblebub]

here is a picture showing some of the local stars including polaris http://www.rickrichards.com/earth/mw_5000lys.jpg

[bibblebub]

in fact, the page that comes from might be slightly more informative http://www.rickrichards.com/earth/earth_8.html

[seadogg]

As the earth tends to wobble about its axis the north star appears to wander over a long period of time but it remains approximately north.

[wildwood]

While we're on about the North... is there a valid reason the North is on top in relation to this planet? I realise there is a need to have a reference point but could South be on top so we view the world the other way around? Then south becomes the top of the world. The 8 yearold next door is driving me nuts with her questions.

[Clanad]

As relates to wildwood's question; I suspect it's due to the fact that most of Earth's land mass and fully 90% of its population live north of the equator. Those facts probably have a lot to do with our historical North[i predilection. Our northness and our reference to [i]Polaris[i] are probably because only after we, as a race, became truly sea going did we discover [i]Sigma Octantis] as an aid to southern navigation...

[beso]

The axis of the earth is tilted to the ecliptic (the plane of the Earth's orbit around the Sun at about 22.5 degrees.

The axis goes through a cycle of precession in 26,000 years. So unless the ecliptic is also precessing relative to the galactic plane to offset the Earth's prescession, the Earth's axis would move from the direction of Polaris by about 45 degrees over 13,000 years.

I cannot find a definitive answer about changes in the Earth's orbital plane relative to the Milky Way but I have no doubt that it is orders of magnitude smaller than the axial precession of the planet.

[beso]

Here is a graphic showing the movement of the celestial pole through precession.

http://en.wikipedia.org/wiki/File:Precession_N.gif

As you can see Polaris won't always be the North Star.

[Charcoboye]

The poles are important only in so much as they are the axis on which our planet revolves. The magneticism of the poles (N and S) is mostly irrelevant except for navigation with a compass (although the fact that we have a magnetic field around the planet is hugely important for our life to exist).

In simple terms the N and S are meaningless in relation to our place within the solar system coz who know which is up? And don't bother mentioning that true north wanders around within the arctic circle or that the earth also tilts on it's axis or that every 100,000 or more years the north pole becomes the south pole and vice versa.

Phew!

[Buenchico]

Wildwood:
Maps like this are widely available in Oz or NZ:
http://blog.ivman.com/wp-content/InvertedWorldMap.jpg

[Arksided]

wow. that looks weird.

[PetitAnglais]

beso, 23.4

[beso]

charcoboye //And don't bother mentioning that true north wanders around within the arctic circle //

Sure, don't mention it because it isn't true. True North doesn't move appreciably. Magnetic North wanders about.

[Charcoboye]

Beso, are you talking about (1)geodetic true north or (2)astronomical true north? Astronomical true north does in fact move as the north star (Polaris) is not exactly aligned with our Earths axis, it's just as near as damnit to that alignment, and so the North Star traces a small circle in our sky and so astronomical true north meanders and is not definitely fixed.

There is another option (3) you're just a pompous smug get who likes to talk down to people from your erudite tower. It's obvious I wrote TRUE and was mistaken in that I meant MAGNETIC north which would have been much easier for you to point out instead of sniggering down your sleeve "yeah don't say that coz its wrong!" - oh wait, it's not wrong!?

[Zacs-Master]

How have I got to 50 years old and never seen an upside down world map before? Very strange indeed.

[mibn2cweus]

leigh47
//I am interested to know how long the North star will apear "North" when viewed from earth.//

Polaris is currently positioned within three/forth's of one degree from the Celestial North Pole. - http://goo.gl/xKVKA

Within the next hundred years (~2102) Polaris will lie within one/half of one degree (less than the Moon's apparent width as seen from Earth) of the CNP before gradually vacating and returning once more to the proximity for which is currently named over the next ~26000 years.
http://stars.astro.illinois.edu/sow/polaris-t.html

[heathfield]

I've had an 'upside down' world map for many years. I learned about them from an Aussie I once met in a bar, who talked about taking a trip 'down north'!

[wildwood]

lol. Thanks for that Chris. Actually, it doesn't look too bad.