The National Astronomical Research Institute of Thailand (Narit) has denied social media speculation about a sighting of the northern lights over a mountaintop in Kaeng Krachan National Park in Phetchaburi.
It says the light in the sky is a reflection from squid fishing boats, not the famed aurora borealis.
Writing on Facebook, Matipon Tangmatitham, an astrophysicist at Narit, said the photos of vivid green light in the sky above the park are "definitely not the northern lights".
He said Thailand's latitude is too far from the earth's magnetic poles, prohibiting the country from seeing the northern lights.
Also, northern lights found along the Arctic and Antarctic are usually transparent so observers can still see stars in the skies. "However, the photos taken at the mountaintop in Kaeng Krachan National Park depict an opaque green layer which blocks the stars," he wrote.
He said there were layers of clouds blocking the stars that night. However, the northern lights usually appear hundreds of kilometres above cloud height, making it impossible for them to appear underneath cloud layers.
He said the green light might have come from the vivid green lights used by squid fishing boats or lights from human activities. In this part of the world, fishermen usually use green light to fish squid at night because of the wavelength visible to squid. "Countries that use green light to fish squid can be found in the Gulf of Thailand. The light is so vivid that astronauts from space stations once reported mysterious green lights shining in the Gulf of Thailand as seen from space," he wrote.
The clarification followed a post by the Kaeng Krachan National Park's Facebook page, which claimed the northern lights had appeared at the top of Khao Phanoen Thung mountain to greet visitors on Nov 3. The post quickly went viral.
The park chief Mongkol Chaipakdee said park visitors had witnessed the same occurrence in the past. Photographers had taken pictures of the green light on top of Khao Phanoen Thung on Nov 2, 2021, and Jan 1, 2022.
He said the green light might have come from the refraction which takes place during the transition from rainy season to winter in Thailand. Light from lower ground might bend when it hits the layers of cloud on top of the mountain.