Shadows disappear as Colombo witnesses rare ‘Zero Shadow Day’

Residents of Colombo witnessed a rare astronomical event at exactly 12.12 p.m. today (April 07) as their shadows vanished momentarily under the midday sun. 

The phenomenon, known as a ‘Zero Shadow Day’, occurs when the sun is positioned directly overhead, causing vertical objects to cast no shadow.
 
This striking event is part of the sun’s apparent northward journey across the Earth’s surface, known as the subsolar point. As the sun reaches the zenith over different locations, its rays fall perpendicularly on those areas, causing shadows to temporarily disappear.
 
The phenomenon began in Sri Lanka at Dondra Head on April 4 and will continue to move northward across the island until April 15.
 
Today, Colombo—one of the country’s most densely populated cities—experienced the zenith moment, attracting the attention of astronomy enthusiasts and curious onlookers. Among them was veteran astronomer Anura C. Perera, who joined a group at the Colombo Municipal Council premises to observe the spectacle.
 
Observers used simple tools—such as a one-foot vertical rod—to witness the moment when no shadow was cast, confirming the sun’s exact overhead position.
 
Meanwhile, similar observations were reported in other parts of the country, including Galle and Anuradhapura, where residents marked the occasion by watching shadows disappear under clear skies.
 
According to astronomers, residents in areas such as Nainamadama and Mahiyanganaya will experience their own Zero Shadow Day tomorrow, as the sun continues its apparent journey across the island.
 
The sun will complete its overhead passage and will move away from Sri Lanka’s Point Pedro on April 15.
 
This rare alignment - Zero Shadow Day - also known as Lāhainā Noon, occurs twice a year in regions between the Tropic of Cancer and the Tropic of Capricorn, according to astronomers.