The sun always rises in the East, right?

Sunrise throughout the year

I like to start my natural navigation sessions with a variation of the above question.

In a large group, I invariably get answers ranging from “yes” through “no” to “it depends”. It depends is the answer I like, this leads to some interesting conversations where the fundamentals of solar movement can be discussed.

Without a doubt, a fundamental understanding of the apparent movement of the sun over time is key to natural navigation. Our ancient ancestors understood this intimately with many henges aligning with the position of the sun at key points throughout the year.

Whilst most people intuitively understand that the sun moves across the sky on a daily basis, and that the days get longer or shorter depending on the time of year, few stop to consider the effect this has on the position of sunrise and sunset throughout the year.

Of course the sun isn’t really moving with respect to the Earth. This apparent movement is due to the rotation of the Earth (daily sunrise and set) and the relationship of the Earth’s axial tilt to the sun throughout the year (longer or shorter days).

Through the year, there are four major events that happen on or around the dates shown and are key in the apparent movement of the sun these being:

  • Spring equinox, March 20th
  • Summer solstice, June 21st
  • Autumnal equinox, September 22nd
  • And Winter solstice, December 21st

Exact dates each year need to be checked as adjustments, like those for a leap year, can change the date by a day or two. It’s also interesting to note that the true definition of these key events is actually a single point in time not the full day. For instance the summer solstice in 2020 was on 20th June at 22:43 in Ely UK.

These seasonal events are convenient points in the year to make observations.

Sunrise throughout the year
Sun as it rises at different times of the year.

The picture above is a composite showing the position of the sun as it rises at winter solstice (right-hand RH) image, equinox (middle) and summer solstice (left-hand LH). Each picture was taken from the same vantage point.

Notice that the LH image is closer to the centre than the RH image. This is due to a combination of increase in the height of the ground to the LH side of the image and also the block of woods obscuring sun rise above the true horizon. The image with the sun sitting nicely on the top of the trees was taken about 55 minutes after the advertised time of sunrise so the position of the sun is ~15 degrees past where it would be at true dawn. The sky is noticeably brighter than the other two images.

The little red dot I added to the image represents the position of the sun at sunrise to the horizon behind the trees. I positioned this using my compass to take a reading against a feature in the trees. This is far more representative of the sunrise point on the summer solstice.

Still I have learnt a lesson and I have found a new vantage point with a clear sweep so will capture images from that point for the forth coming year.

Yes, there were a few early mornings involved!

So does the sun rise in the east? Yes, it does on two days of the year, the equinoxes. At all other times of the year it is transitioning between the extremes shown at the two solstices. Exact numbers will vary, depending on your latitude, but for Cambridge UK where the above pictures were taken, sunrise on the summer equinox was at 48 degrees or just past North East whereas sunrise on the preceding winter solstice had been at 129 degrees or just before South East; a massive difference in sunrise position of 81 degrees!

Understanding the deviation of the position of sunrise throughout the year is another tool in the toolbox of understanding the natural features around us and how we can use these to help us find direction.

As we approach the winter solstice for 2020, why not start taking your own observations? Online resources such as timeanddate.com have a plethora of data that helps explore the apparent movement of the heavens with respect to our position on the planet.

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