The skies of Mecca will witness an annual astronomical phenomenon tomorrow, Sunday, when the sun will align directly above the Kaaba, causing the shadow of the Kaaba and all objects in the area to disappear. This will be the first time in 2023 that the sun will align directly above the Kaaba, occurring at 12:18 PM Mecca time, coinciding with the noon call to prayer.
The Astronomical Society in Jeddah explained that "at the moment of alignment, the sun will reach its highest point, approximately 90 degrees, resulting in the complete disappearance of the shadow of the Kaaba and all objects in Mecca, making the noon shadow zero."
It was noted that "regions located at latitudes lower than 23.5 degrees North or South experience the phenomenon of solar alignment with the Kaaba twice a year, but at different times depending on the latitude of that location, which is a unique occurrence for a few areas between the equator and the Tropics of Cancer and Capricorn."
Mecca experiences this solar alignment phenomenon twice a year due to the tilt of Earth's rotation axis at an angle of 23.5 degrees, leading the sun to "apparent" travel between the Tropic of Cancer to the North and the Tropic of Capricorn to the South, passing through the equator as the Earth orbits the sun.
Because of the Kaaba's unique position between the equator and the Tropic of Cancer, this phenomenon occurs twice: first when the sun moves from the equator to the Tropic of Cancer in May each year, and second when the sun returns south to the equator from the Tropic of Cancer in July each year.
In a related context, the Emirates Astronomy Society announced that the noon shadow will disappear in the southern regions of the state, including Umm al-Zumul, Jaisura, Muzairi, Liwa, Madinat Zayed, and Al-Qou. The chairman of the society, Ibrahim Al-Jarwan, stated that the sun will align in these areas from June 6 to July 7, with the absence of the noon shadow around 12:25 PM UAE time.
Historically, the solar alignment phenomenon has been used to accurately determine the direction of the Qibla. This is done by erecting a vertical stick on the ground at the time of alignment, and the shadow is used to define the Qibla, with the direction opposite the shadow indicating the Kaaba for residents in regions far from Mecca in Arab countries and neighboring areas near the North Pole, Africa, Europe, China, Russia, and East Asia.
This phenomenon is also utilized in various mathematical calculations, such as calculating the circumference of the Earth without the use of modern technology, employing simple principles from geometry that date back over 2000 years, and serves as direct evidence of the Earth's roundness.