My thanks to Mark Evans who not only flew over from Oman for a course, but also sent me this great time lapse photo from Oman.

Mark is the General Manager of Outward Bound Oman, which does not sound like the worst job in the world to me! Outward Bound Oman, under Mark’s leadership, is teaching young Omanis many outdoor skills, including traditional methods of desert navigation.

Time for a bit of fun. Which way are we looking in this picture and why?

Answers by email please. I’ll post the correct answer in a couple of days.

Update.12/05/11.

We are looking just south of west. approx 255 degrees. Orion’s belt can be seen setting about one third the way in from the right. The arcing to the right is anticlockwise around the North Celestial Pole, to the left the stars are arcing clockwise around the South Celestial Pole. The few stars that appear to be moving in a straight line are marking the celestial equator and where they cross the horizon (the imaginary sea level one) will be due west.

One way we can tell it is west, not east, is because of the shape of Orion: the bright orange Betelgeuse (Beetlejuice) of the hunter’s top left shoulder is above his belt. Other stars visible include the brightest of the lot, Sirius (half way in and low), Procyon (half way in and high), Castor and Pollux (top right, behind tent cord) among others.

Well done to those who got it. Better luck to those who were only out by 180 degrees, bizarre though it sounds you were closer to the right answer than if you had said north or south.

Orion and his sword were first to offer their greetings and then I noticed Jupiter still visible in the southwest. Sirius, Betelgeuse, Capella, the Plough and Polaris sketched out some order in the celestial sphere.

The moon was close to setting and was lighting up rows of fluffy cumulus clouds on their western edges. As time passed the clouds lost their bright white western edges, but gained pink and orange eastern ones. They moved sedately towards the northeast, signalling the start to a fine day. (Photo to the right was taken a few minutes ago.)

My thanks to Kevan Hubberd for sending in the idea about using Orion’s Sword as a way of finding south.

Orion’s Sword can be seen in the image to the left as the short vertical line of ‘stars’ under Orion’s Belt.

The Sword does indeed point to a spot on the horizon that is close to due south when the Sword is near vertical (as in this image), but it is a less dependable guide when it is well off-vertical, ie. when it is lower in the sky.

Technical bit for natural navigation zealots only: The reason that the Sword is more accurate when vertical is that it makes a line in the sky that is parallel to the line towards the south celestial pole. When vertical this line intersects with the horizon at a point very close to due south, but at times when the sword is closer to the horizon, ie. closer to east or west, then the point of intersection will also mover closer to east or west respectively. The extreme would be the moment when the sword rises in the east or sets in the west.

Bonus trivia: The Orion Nebula, a region of massive star formation, can be seen as the bright orange ball that forms the middle of the three ‘stars’ of the sword. NB. It is not the huge bright orange star to the top left, that is Orion’s shoulder and is called Betelgeuse or ‘Beetlejuice’, from the Arabic words for ‘giant’s shoulder’.

“He stood and carefully examined the sky, to ascertain the time of night from the altitudes of the stars. The Dog-star and Alderbaran, pointing to the restless Pleiades, were halfway up the Southern sky ,and between them hung Orion, which gorgeous constellation never burnt more vividly than now, as it soared forth above the rim of the landscape. Castor and Pollux with their quiet shine were almost on the meridian: the barren gloomy square of Pegasus was creeping round to the north-west; far away through the plantation Vega sparkled like a lamp suspended amid the leafless trees, and Cassiopeia’s chair stood daintily poised on the uppermost boughs. ‘One o’clock,’ said Gabriel.”

…

“The sky was clear – remarkably clear – and the twinkling of all the stars seemed to be but throbs of one body, timed by a common pulse. The North Star was directly in the wind’s eye, and since evening the Bear had swung round it outwardly to the east, till he was now at a right angle with the meridian. A difference of colour in the stars – oftener read of than seen in England – was really perceptible here. The sovereign brilliancy of Sirius pierced the eye with steely glitter, the star called Capella was yellow, Alderbaran and Betelgeux shone with a fiery red.
To persons standing alone on a hill during a clear midnight such as this, the roll of the world eastward is almost a palpable movement. The sensation may be caused by the panoramic glide of the stars past earthly objects, which is perceptible in a few minutes of stillness, or by the better outlook upon space that a hill affords, or by the wind, or by the solitude; but whatever be its origin, the impression of riding along is vivid and abiding. The poetry of motion is a phrase much in use, and to enjoy the epic form of that gratification it is necessary to stand on a hill at a small hour of the night, and, having first expanded with a sense of difference from the mass of civilized mankind, who are dreamwrapt and disregardful of all such proceedings at this time, long and quietly watch your stately progress through the stars. After such a nocturnal reconnoiter it is hard to get back to earth, and to believe that the consciousness of such majestic speeding is derived from a tiny human frame.”

I will try not to spoil the moment by pointing out that if Castor and Pollux were ‘almost on the meridian’ then it would be hard to see the square of Pegasus in the way that Hardy describes. I will try but fail. Rare is the fiction writer who has ever attempted to portray the night sky without betraying their lack of fundamental understanding. Hardy’s efforts are much better than most, as you might expect from a literary giant. So few writers appreciate that the stars, if described in detail, must be fixed in time, both nightly and annual, as well as in direction. There is nothing casual or random in the appearance of the night sky at all. Fortunately the errors are rarely obvious enough to spoil a good story!

‘In Orion these [stars] are Rigel, Betelgeuse and Bellatrix; in Canis Major there is Sirius – and even Canis Minor, which essentially consists of only two stars, has the very bright Procyon. These are familiar names, but not perhaps for astronomical reasons. Bellatrix and Sirius are probably better known now as characters in J.K. Rowling’s Harry Potter books, while Betelgeuse was the title of a Tim Burton film, albeit with a different spelling [Beetlejuice].