This fantastic photo was taken by the expedition photographer, James Walker.

Thanks, James, for permission to use it here. Do check out James’ website, there are some stunning images, but only after you’ve had a go at answering the questions below.

Which way are we looking in this picture?

Bonus: roughly what latitude was the photo taken at?

Good luck! I’ll post the answer here in a few days.

Photography tip from a pro: The tomb in the picture was not illuminated and James achieved this effect by keeping the shutter open whilst he climbed up to the tomb. Whilst there, he used a flash to illuminate the tomb, making sure that his body was always between the flash and the camera, to avoid any of the light from flash spilling directly into the lens.

————

On a different subject, the first review of The Natural Explorer has come in:

“The Natural Explorer is an essential part of any outdoor/nature writing library and it works in several ways. It’s a cogent paean to the glories of nature, a subtle manifesto, a call to arms to get out and appreciate the wonders of the natural world. It’s also full of wonderful examples of how to better read, understand and connect with the landscape.”

Damian Hall, Country Walking magazine

Congratulations Sim on taking this fantastic photograph and allowing me to share it and thanks Mark for sending it my way.

To celebrate this great pic, I thought a little quiz would be fun. Or to be more precise, several shades of the same question…

To make this more interesting I’m going to give you the opportunity to test yourselves at the level you feel most comfortable with. Anyone who has been on my Beginner’s Guide to Natural Navigation course or read The Natural Navigator book, should be able to crack this at one level at least.

Depending on your level of confidence try one of the questions below, A is very difficult, B slightly easier etc. (Don’t read them all first though as there are clues in B, C and D which make it a little easier.)

A) Just by studying this photograph, can you work out which way we are looking in this photo and the latitude the picture was taken at?

B) The photograph was taken in the northern hemisphere. Can you work out which way we are looking in this photo and the latitude the picture was taken?

B) The photograph was taken on the east coast of Masirah Island, Oman, latitude 20 degrees north, what direction are we looking in the picture?

D) The picture was taken on the east coast of Masirah Island, Oman, latitude 20 degrees north. During the time lapse needed to take the photograph the stars rotated clockwise. What direction are we looking in the picture?

Answers by email or Twitter. No prizes other than honour and glory, of sorts

A big thank you to Sim and Mark, for respectively having taken this picture and sending it my way. It’s a cracker and deserves to win an award in my opinion. I’m not the sort of person to sit back and wait for other people to realise that an award should be given to someone, so I hereby award Sim with the inaugural The Natural Navigator Astronomical Photograph of the Year award 2011!

UPDATE:

Look away now if you don’t want the answer yet…

We are looking SSE. The south celestial pole is to just below the bottom right of the picture. The stars we are looking at are those between Achernar (bright streak on right) and the constellation Lepus (left of picture). Well done to all who got it.

If you want to see some pretty thorough workings, then this is not a bad place to find them:

http://thisteacherslife.wordpress.com/2012/01/06/seeing-stars/

This instrument is as simple as they get: it works by forming a triangle. If you know the base of a triangle (the fixed length of twine from eye to instrument) and you know the height of the triangle (the number of fingers counted up from the horizon), then you have a fixed angle to the horizon. This is the ancestor of nearly all navigational instruments prior to electronics. (In fact the triangulation used has a lot in common with the way GPS works, but that is another story.)

How does it work in practice?

Here’s the simplest example: the Pole Star (Polaris, North Star) will be the same angle above your horizon as your latitude. At the North Pole it is vertically overhead and you are at 90 degrees north. At the Equator it sits on the horizon and your latitude is 0 degrees.

On a more practical level… Imagine you set out west from a desert camp on a long journey west into the Sahara. If you measure, as accurately as possible, the number and fraction of fingers that the Pole Star is above your northern horizon then you have a measure of your latitude. You can confidently explore the desert for as long as resources allow, then, when it is time to head home you line your kamal up with the Pole Star. If the star is higher (more fingers) you are north of your camp, if there are fewer fingers you are south of it. All you do is head north or south until the right number of fingers line up with the star and then head back east. You will bump into your camp. If you have been skilful enough! (The same of course applies to any ocean journey).

There are lots of slightly more convoluted (and fun) ways of using this simple instrument, but that is the crux of the matter.

Once this makes sense it is very easy to see how the whole history of navigational instruments developed. They mostly boil down to a desire to measure first angles and then time more accurately. The backstaff, octant and sextant are just the pernickety (and more accurate) grandchildren of the kamal.

You can make a kamal at home using cardboard and string. I nearly mentioned double-sided sticky tape then, but its too simple for even that. Bad luck, Blue Peter! With a bit of luck they’ve already got one somewhere, one that they made earlier…

We started with theory indoors at the offices of Outward Bound Oman, with the help of planetarium software and makeshift whiteboards (paper Sellotaped to a cupboard). After three hours of theory, it was time to head out in 4x4s for a 3 hour drive into the desert, for some more practical training.

We tracked the sun down to the horizon and confirmed that it had indeed set a good 15 degrees south of west. We looked at the way the wind had shaped some small plants and then how the crescent moon was pointing perfectly south. After some dahl and rice it was time to sit on the mats on the sand and get apply the astronavigation theory to the night sky. Jupiter beamed brightly from the east.

At a latitude of 23 degrees and at that time of year the Plough is too low to use, so we focused on Cassiopeia. I also pointed out the Navigator’s Triangle and the way the ‘cross’ of Cygnus can be used to find north. The final method we used was the square of Pegasus. More importantly we studied the movement of the stars, before settling in for an early night.

The following morning there was too much cloud cover for stars so we packed up and got ready to make the most of the early morning cool for some daytime exercises. Picking my mat up off the sand I was confronted with the realisation that I had been sleeping over an unwelcome guest: a scorpion (see photo below). This was the first of many encounters in 48 hours. (That night, I felt a tickle on my foot as I went for a pee and a flash of the headtorch revealed that worse than poor aiming, it was another good-sized scorpion crawling over my foot. Like hornets and other unwelcome ‘friends’, scorpion sightings are fortunately much more frequent than scorpion stings, which remain rarer and much less deadly than their reputation. That was hopefully of some comfort to Gary Lyon, a consulting instructor, who was sleeping nearest me and received a nasty scorpion sting on his foot. He was much more stoical about the whole thing than I would have been!)

We spent the morning looking at clues in the sun, the dunes, the trees, the wind and clouds. Then we did some exercises in gauging distance using paces and perspective.

We sat out the midday heat in the shade, which gave me a chance to have a really fascinating discussion with Eric Staples. Eric is an authority on medieval Arabic navigation, he has personally overseen the rebuilding of many historical Omani sailing vessels and has a passion for historical Arabic navigational techniques. Together we spent a wonderful couple of hours trying, successfully I believe, to unlock some secrets in a Arabic text regarding the use of the Pole Star by reference to the lunar mansions. It was great teamwork, Eric’s knowledge of medieval Arabic is of the highest order and my familiarity with some of the techniques they referred to helped us solve some tricky passages. Great fun, but not for the faint-hearted!

Later that day we were able to use a ‘kamal‘ that Eric had fashioned from traditional materials of wood and twine. This simple instrument was used by the earliest sailors and desert travellers as a means of establishing latitude. More on that another time.

I also was privileged to spend time with Dr. Andrew Spalton, the leading conservationist authority in Oman.

On the final morning at 5am we enjoyed good sightings of Orion, Leo, Mars, Gemini, Procyon, Taurus, Pleiades and a whole host of others. We used Capella and Auriga to find north. As the sun rose, 15 degrees south of east, it was sadly time to go.

My heartiest thanks to Mark Evans at Outward Bound Oman for inviting me to Oman and to his instructors for the patience and enthusiasm. What a country!

In the photo at the top we are looking north along linear sand dunes. These dunes form when two complementary winds channel the sand into long, often dependable dunes. The winds had clearly blown more from the southeast than the southwest, as the eastern flank was the firm shallower windward side and the western side was the softer steeper slip-face.

It was a beautiful full moon last night and I got to experiment with a new lens that I have bought. Still a long way to go until I take a photo of the moon that I am happy with, but always learning which is satisfying.

The phase of the moon appears the same all over the world, but the orientation changes depending on your latitude. In other words, a full moon will be full all over the world, but its features may appear upside down from the opposite hemisphere. When high in the sky, crescent moons will appear closer to ‘vertical’ at higher latitudes and ‘horizontal’ nearer the equator.

The way to remember roughly what direction a full moon will rise is to remember that a full moon is opposite the sun. We are approaching midsummer and so the sun will set closer to northwest in places like the UK at this time of year – the moon therefore rises closer to southeast. In winter the full moon rises closer to northeast. This is all due to the angle of the Earth’s poles relative to its orbit around the sun, that all important 23 1/2 degree ’tilt’.

—-

My thanks to Nick Tile, who attended the course yesterday and has just forwarded this fantastic link to a website that shows you how to make your own ‘solargraph’ using a homemade pinhole camera.

An interesting article on the BBC website today about the seasonal habits of Puffins.

The most interesting thing other than learning more about the puffins’ whereabouts was the method they used for understanding where the birds were at any one time. Using ‘geolocator tags’ that logged the time of sunrise, sunset the research team were able to deduce their location.

‘The loggers work by measuring light levels, recording when dawn and dusk occurs each day.

With this data, researchers can calculate day length, when midday occurs, and the daily longitudinal and latitudinal co-ordinates for the individual bird.’

The tags also detected when the birds’ feet were wet, the hope being that this would give information about when the birds were airborne, but the puffins foxed the researchers here: they like to tuck their feet up into their plumage when asleep. Their feet were dry even as they bobbed on the surface of the sea.

It is navigationally interesting because of its declination or ‘celestial latitude’. At 19 degrees north it passes overhead a lot of major cities, including Honolulu, Mumbai and Mexico City.

The easiest way to find Arcturus is to follow the the handle of the Plough on its curved path away from the ‘saucepan’. The star that can just be seen in the top right of the photo is the end of the saucepan handle.

Sticking with a midsummer theme for another day, I came across this picture today. It was taken in a place called Uttakleiv in northern Norway. The time lapse shows how the sun does get lower, the angle being directly related to the latitude, but at this high latitude even its lowest point is not below the horizon. I was fortunate enough to witness the midnight sun in Kiruna in north Sweden a few years ago, but my photos were a lot less dramatic than this. Something to do with the fact I had flown about ten hours that day in a tiny aircraft. That and the fact that I am not a very good photographer.

Tristan


I managed to rope in a friend at the end of an evening’s BBQ and together we plumb-bobbed Polaris, set out two posts and then strung a string between them. We checked with a compass and, despite the evening’s beers, we were actually almost spot on!

The next day we checked the shadow at 1.00 (12 noon GMT) and found this lined up on our string. Impressed or what!

Richard

——————

Hi Richard,

I can see I’m going to need to come up with some sort of merit/badge/star system just to complete the back to school experience!

A link that I will have mentioned on the day is here:

http://aa.usno.navy.mil/data/docs/AltAz.php

If you plug in your latitude and longitude, it will give you the altitude and azimuth of the sun (or moon) for a whole day by GMT. Due south is often very close to clock midday, but it can wander off it depending on your longitude and because of something called the ‘equation of time’.

All the best,

Tristan