Orion/Orion's Belt - can it be used to find south?

Robert Wilson

Robert Wilson

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A line from the top through to three bright stars at the bottom seem to me to point North-South. Indeed, extending a line northwards points to Polaris.
Would using Orion be a reliable way to find north/south if Polaris was obscured? If so, would Orion be visible 365 nights a year in the northern Hemisphere?

It's incredibly bright up here at the mo :encouragement:

Over to you astral-nav guys.

Thanks
 
There are three bright stars in Orion, known as the belt, but they are in the middle.
Orion is not visible in the UK in the summer as it rises during the day.
There are many alignments of stars that point to Polaris as the sky seems to rotate around it. The most commonly cited is the two stars on the blade of the Plough.
 
The principle is sound, but I'm not sure how exact the alignment is - and I no longer have a copy of a star atlas to check. To work accurately from any point on earth, you would need two or three stars reasonably close together on the celestial equator. Orion's belt must come close to that.
 
No.
Not the way you describe it. It will not point north south. It would only work if Orion is on your meridian. although it will point to the north star. I never heard it used as a marker or pointer in this way. Having said this. I does help you orientate yourself if you have some familiarity with the constellations and the stars. And you can figure it out.
As a navigator I am not an astronomer. Patrick Moor would be quite unimpressed with my knowledge of the night sky. Finding most but not all of the 50 main navigational stars would be my limit when doing so regularly back in the day when I would routinely do compass errors at night.
Depending upon the time of year it may be visible rising, setting in the evening, or rising ,setting in the morning.
Orion's belt is virtually on the celestial equator(slightly S)s.
Orion is probably the single most recognisable constellation. In the Night sky. It can also be seen at some during the night time from almost any latitude. I always used it as a primary way of starting to identify the constellations.
The principle stars in Orion are very well known. Funny I cant name any of the belt stars. The belt point down to Sirius. The Top left or Betelgeuse or Beetel juice, Top right Belatrix, bottom right Rigel bottom left I forget. if you look in a curve out above N to the right you will see Aldebaran in Taurus, a curve out above to the left and you will see castor and pollux in Gemini. They are on the ecliptic(the suns path)
roughly on a line out from the top to Belatrix though Betejuice will point to Castor
The plough or dipper. Is much further north and In the UK circum polar(doesn't set) so it will point you to the N Star or Polaris all night. The two on the end Merak and Dubhe point to Polaris. Alkaid is at the end of the handle. If you keep a curve going back from the handle you will see Arcturus and on down to Spica which is in Virgo.
I like to have a star chart to look at. At night.
From the Plough and Orion if you have a star chart you can find the other constellations quite easily. Or a cell phone with an app(my son has its quite good)
Pegasus becomes easy to find. Pleiades is just beside Taurus.
Unfortunately the only star which will always give you N and S is Polaris. All the others rise in the east and set in the west unless they are circum polar in which case they go right around from west back to east.
In the South. The Southern Cross is a good indicator ad you can still se Orion.
 
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Presumably he means Orion's sword. This might be useful, about on a par with the growth pattern of trees, but maybe better than nothing. Altogether, a nebulous idea.
 
Thanks folks.
I thought it was a flimsy hope, to be able to use Orion for north/south, but having seen it so often recently on my midnight walks with pooch and it always appearing in the same orientation I thought I'd check.
Not that I can navigate by the stars, or even name/find any of the constellations, but for over sixty years Polaris and The Plough have been my guides.

I once navigated an over-loaded 38tonne articulated wagon through the side streets and estates of London using Polaris. Very relieved to at last reach the North Circular Road and eventually the M1 :encouragement:
 
The line of stars do lie on a great circle that is pretty close to touching Polaris (and therefore Crux) you wont know how far to extend the line to determine your north or south.
Imagine a friend standing due East from you, pointing North. It is only at infinity that his line intersects your north, it is not possible to visualise that point so it is not much use.
If, however you have 2 such markers you could make it work.
 
I take your point (and others'). I suppose I was pondering that if (a big if) I was at sea at night, with sketchy cloud cover and a complete failure of all nav equipment and the only thing I could see that I recognised was Orion, then would I be correct in assuming the "sword" pointed southwards?
It appears that I would be to some extent able to somewhat discern my preferred direction.

All the above posts have been most informative.

Thanks, one and all
 
No.
The sword would only point south if Orion was on your meridian. it could be pointing NE or NW or any direction in between.

By using Orion to identify a couple of the zodiac constellations. Ie Taurus Gemini and leo. you could get an idea where the ecliptic is. and from this figure out approximately where N and South are.

If you happened to have a star chart. or finder you could line it up with Orion and use it to identify approximately where Polaris and N is along with the ecliptic. From which you could figure out directions.

Even in the S hemisphere you could align a star chart to the stars you can see if you can identify them.

Very roughly even without a star chart. as you pointed out. Polaris will be approximately 90 deg, or half way across the sky from Orion's Belt through his head.
Looked at another way. take a line up through Orion from the horizon all the way to the other horizon through your Zenith.(right over your head) Polaris should be approximately the same height above the opposite horizon as Orion's belt. this will give you an approximate N. from this you can approximate the other directions.

Personally I would tend to use the wind and swell. to guesstimate direction. If I know from having been able to see the wind and swell earlier when I did know the directions from the sun. The wind may change but the swell will still come from the same direction for hours.
 
The leading star on Orion's Belt called Mintaka rises due east and sets due west. So when it is fairly close to the horizon, you have one cardinal. Bit of estimating will give you all the others.
 
The only constellation due south is the Southern Cross you can see it at 20 degrees north i.e. southern Caribbean. Picture here: http://earthsky.org/?p=2992. Leaving the last Venezuelan out island, Los Aves, we had complete electical failure and we wanted to leave at night to reach Bonaire at dawn. We were seriously lucky we were heading due west downwind and could see the the pole star the southern cross and Venus, that follows the sun. So we aimed the bows at Venus and checked othe other two occasionally.
 
As stated above the central star in Orion's belt sits on the celestial equator ( declination of about 1 degree if my memory serves ) and so always rises and sets 'due east' and 'due west'. With a bit of practice you can estimate the rising or setting point just by observation for a few hours after Orion rises or before it sets.

If you can see the Southern Cross it is simple matter to find 'south' at any hour of the night.. lookee here ... http://www.teara.govt.nz/en/diagram/7486/navigating-by-the-southern-cross
 
Robert Wilson said:
I take your point (and others'). I suppose I was pondering that if (a big if) I was at sea at night, with sketchy cloud cover and a complete failure of all nav equipment and the only thing I could see that I recognised was Orion, then would I be correct in assuming the "sword" pointed southwards?
It appears that I would be to some extent able to somewhat discern my preferred direction.
All the above posts have been most informative.
Thanks, one and all
Click to expand...

If you're interested in all this you might enjoy a play with Stellarium. Amongst other things you can replay Orion's progress through the sky (say) tonight and see how it all lines up.

http://www.stellarium.org/en_GB/

Also:

The Natural Navigator Pocket Guide, which includes michael_w's Mintaka West/East trick:
https://www.amazon.co.uk/Natural-Na...1336&sr=1-2&keywords=gooley+natural+navigator

Pencil, Paper & Stars:
https://www.amazon.co.uk/Pencil-Pap...gation-ebook/dp/B00FXXZ96Y/ref=dp_kinw_strp_1

Finally, IMHO, Marvin Creamer's great too:
http://www.furledsails.com/article.php3?article=774
http://www.furledsails.com/article.php3?article=775
 
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Mark-1 said:
If you're interested in all this you might enjoy a play with Stellarium. Amongst other things you can replay Orion's progress through the sky (say) tonight and see how it all lines up.

http://www.stellarium.org/en_GB/

Also:

The Natural Navigator Pocket Guide, which includes michael_w's Mintaka West/East trick:
https://www.amazon.co.uk/Natural-Na...1336&sr=1-2&keywords=gooley+natural+navigator

Pencil, Paper & Stars:
https://www.amazon.co.uk/Pencil-Pap...gation-ebook/dp/B00FXXZ96Y/ref=dp_kinw_strp_1

Finally, IMHO, Marvin Creamer's great too:
http://www.furledsails.com/article.php3?article=774
http://www.furledsails.com/article.php3?article=775
Click to expand...

Thank you.
I think I have a headache coming on - where's the Rum? :)
 
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