The Welcome to Emerald sign.
The Welcome to Emerald sign. Contributed

Finding a point of reference

I AM not really a local, although we have lived here for five years and I believe a local has to have a few more years under their belt to claim this status.

So to all you true locals out there I ask you two questions, where is the Tropic of Capricorn and at what point does it pass through or near Emerald?

Why, I hear you ask? Well I had a call from a local lady a couple of weeks ago informing me that a source of local information regarding the Tropic of Capricorn was incorrect.

Upon doing a little research the lady was most definitely correct, and all efforts have been made to reflect this in the information.

I for one have always pondered the where's, the why's and the what for's of the Tropics in general and seeing that the Tropic of Capricorn runs right through the Central Highlands I have carried out a little research, the results of which I am happy to share with you.

The Tropic of Capricorn gets its name because the sun was in the direction of the constellation Capricornus (capricorn is Latin for goat horn) at the December Solstice (our summer solstice). This naming took place 2000 years ago and over this time things have changed considerably.

In modern times the sun appears in the constellation Sagittarius during this time. The change is due to precession of the equinoxes. The word "tropic” itself comes from the Greek trope, meaning turn, change in direction or circumstances, referring to the fact that the sun appears to "turn back” at the solstices.

The Tropic of Capricorn is the dividing line between the Southern Temperate Zone to the south and the tropics to the north. The Northern Hemisphere equivalent is the Tropic of Cancer.

To bring it right back to basics, the Tropic of Capricorn is the southernmost latitude where the sun can be directly overhead.

The position of the Tropic is not fixed and as of August 6, 2017, its latitude is 23°26 13.2 (or 23.437°) south of the Equator, but it is very gradually moving northward, currently at the rate of 0.47 arcseconds, or 15 metres, per year.

On mainland Australia, the Tropic of Capricorn passes directly through or very near to Paraburdoo and Newman in Western Australia, Ikuntji and Alice Springs in the Northern Territory, Longreach, Rubyvale/Sapphire, Emerald and Rockhampton in Queensland.

So back to my original questions, where is the Tropic of Capricorn and at what point does it pass through or near Emerald?

Research shows that the Tropic of Capricorn passes north of Emerald somewhere near the Theresa Creek crossing and as far as I can see there is nothing to mark its passing.

The two references to the Tropic of Capricorn at the northern entrance to Emerald were last correct back in back in 1864.

Maybe an artist or sculptor could produce art to reflect the presence of our Tropic of Capricorn.