Belt of Venus

We’ve had some clear, cold and crisp mornings over the last few weeks, and you may have noticed the western horizon becoming awash with a band of pale pinks and blues in the twilight just before sunrise, creating a scene reminiscent of a watercolour painting. If you have, then it’s more than likely you have spotted the Belt of Venus, a subtle atmospheric phenomenon that creates a mesmerising gradient of colours in the sky at both sunrise and sunset. However, don’t be fooled by the name. It has nothing to do with the planet Venus but is instead associated with the girdle or belt worn by the Greek goddess Aphrodite, the Roman counterpart of Venus and the goddess of love and beauty.

Belt of Venus - Loch Sunart, Resipole, Sunart

The Belt of Venus is what is known as the anti-twilight arch, a phenomenon that appears as a distinct pinkish or rosy band of light just above the horizon opposite the setting or rising sun. It is visible during both dawn and dusk, adding a sense of wonder and beauty to the transitions between night and day. So much so that it is named after the magical girdle of Aphrodite, a legendary artifact imbued with extraordinary powers.
 
This girdle, also known as the Cestus, was said to have been woven from the finest threads of gold and adorned with intricate patterns that shimmered like the dawn. Its enchantment was unparalleled because it held the divine ability to inspire love and desire in anyone who beheld its beauty and Aphrodite, the Greek goddess of love and beauty, wielded it to captivate gods and mortals alike, bending their wills to her favour.
 
Its power was not merely physical; it is said to have emanated an aura of irresistible charm that could soothe the fiercest hearts and ignite the deepest passions. It symbolised the quintessence of feminine allure and the profound impact of love, and it gave Aphrodite dominion over the most potent of human emotions, rendering her the ultimate arbiter of harmony and discord in relationships. Therefore, it is little wonder that the captivating band of pink and rose hues that emerges out of the darkness during twilight, instilling a sense of timeless beauty, has been associated with the Cestus and named the Belt of Venus.
 
The Belt’s colours are formed by the scattering of sunlight through the Earth's atmosphere during twilight, when the sun is just below the horizon. It is then that the sun’s rays must travel through a greater thickness of the Earth's atmosphere compared to when it is higher in the sky. This increased path length causes shorter wavelengths of light, such as blue and violet, to scatter more than the longer wavelengths of red and pink. The result is that the remaining light which reaches our eyes is predominantly composed of the pinkish hues that we see just above the horizon.
 
The Earth's shadow can play a significant role in enhancing this phenomenon. The shadow is caused by the Earth obstructing the direct path of sunlight, to create a dark blue band low down on the horizon and opposite the sun. This dark blue shadow contrasts sharply with the pinkish and rose colours of the Belt of Venus above it, thus making the phenomenon even more striking. This is particularly so when it is observed over clear horizons, such as the ocean or open landscapes, where the full expanse of the sky is unobstructed.
 
So, if you find yourself at the coast during sunrise or sunset, and you have a clear view of the horizon, take a moment to marvel at the Belt of Venus as it emerges above the Earth’s shadow to paint the sky with a band of breathtaking pinks and blues. Take a moment to reflect on how ancient myths connect us to the celestial rhythms that govern our world. And take a moment to pause and appreciate the fleeting moments of beauty that nature offers.