Sri Lanka is experiencing a remarkable astronomical event today, September 5, as the sun passes directly overhead several locations across the island at approximately 12.08 noon. The locations experiencing this solar zenith phenomenon today include Moratuwa, Kesbewa, Handapangoda, Idalgashinna, Yudhaganawa, Kotiyagala, and Panama. This event is part of a broader period during which the sun tracks directly over Sri Lankan latitudes, offering a fascinating natural occurrence that locals and astronomy enthusiasts can observe with their own eyes.
What Is the Solar Zenith and Why Does It Happen?
The solar zenith, commonly referred to as the sun being "directly overhead," occurs when the sun reaches its highest point in the sky and sits at a precise 90-degree angle above the horizon at a specific location. During this moment, vertical objects cast no shadow whatsoever, creating a striking and unusual visual effect that many people find both surprising and captivating.
This phenomenon is directly linked to the Earth's axial tilt of approximately 23.5 degrees and its annual orbit around the sun. As the Earth moves through its yearly journey, the sun appears to shift its position relative to the Earth's surface, moving between the Tropic of Cancer in the north and the Tropic of Capricorn in the south. Sri Lanka, being a tropical island nation located close to the equator, falls within the belt where the sun can appear directly overhead twice a year.
The apparent southward motion of the sun during this time of year is responsible for the current event. As the sun makes its gradual journey toward the southern hemisphere following the summer solstice, it crosses over the latitudes corresponding to various parts of Sri Lanka, creating these brief but memorable zero-shadow moments.
The September Window: August 28 to September 7
According to meteorological and astronomical observations, the sun is positioned to pass directly over the latitudes of Sri Lanka during a window spanning from August 28 to September 7 this year. This approximately ten-day period sees different locations across the island experiencing the overhead sun phenomenon on different dates, depending on their specific geographic latitude.
Today, September 5, it is the turn of Moratuwa, Kesbewa, Handapangoda, Idalgashinna, Yudhaganawa, Kotiyagala, and Panama to experience this event. These locations, spread across different parts of the island, share a common latitude that aligns precisely with the sun's current apparent position in the sky. The exact timing of 12.08 noon local time marks the peak moment when the sun reaches its zenith over these areas.
Residents and visitors in these towns and villages had the opportunity to witness a truly unique natural spectacle by simply stepping outside and observing vertical objects such as lamp posts, flagpoles, or even a straight stick planted in the ground. At the precise moment of solar zenith, these objects appear to have no shadow at all, as the sunlight falls perfectly straight down from directly above.
Locations Experiencing the Overhead Sun Today
The seven locations experiencing the solar zenith today represent a diverse cross-section of Sri Lanka's geography. Moratuwa and Kesbewa are bustling urban and suburban areas located in the Western Province, forming part of the greater Colombo metropolitan region. These densely populated areas gave thousands of residents the chance to witness the phenomenon in an urban setting.
Handapangoda, another location in the Western Province, also falls along today's zenith latitude. Moving further into the island's interior, Idalgashinna is a scenic town nestled in the hills of the Sabaragamuwa and Uva provinces, known for its tea estates and cool climate. The sun passing directly overhead in such an elevated location adds an extra dimension to the experience.
Yudhaganawa and Kotiyagala are located in the Uva and Eastern provinces respectively, while Panama sits along Sri Lanka's beautiful eastern coastline. The geographic spread of today's locations illustrates how the solar zenith line cuts across the island from west to east, touching communities with vastly different landscapes, cultures, and elevations.
How to Observe the Zero-Shadow Moment Safely
Observing the solar zenith is a straightforward and accessible experience, but it is essential to do so safely. Never look directly at the sun with the naked eye, as this can cause serious and permanent damage to your eyesight. Instead, focus on the shadows, or rather the absence of them, cast by vertical objects around you.
A simple and effective method is to place a straight stick or ruler vertically in the ground and watch as its shadow gradually shortens and disappears around 12.08 noon. You can also place a coin or circular object on a flat surface and observe how the shadow aligns perfectly beneath it at the moment of zenith.
A Reminder of Sri Lanka's Tropical Position
This annual event serves as a vivid reminder of Sri Lanka's privileged position as a tropical island nation. The overhead sun phenomenon is something that only locations between the Tropics of Cancer and Capricorn can experience, making it a uniquely tropical spectacle. As the sun continues its southward journey over the coming days, other Sri Lankan locations will take their turn in experiencing this extraordinary zero-shadow moment before the window closes on September 7.