SINGAPORE - An orange vertical line in the sky on Dec 10 – which was visible from several areas in the north – sparked bewilderment and curiosity as Singaporeans quickly captured the moment with their cameras and uploaded it to social media platforms.
One such post, which was uploaded on Facebook group CloudSpotting and SkySpotting Singapore, caught the attention of hundreds of people.
Ms Alice Ng, 50, who uploaded an image of the night sky in Yishun, told The Straits Times that “the orange light in the sky was glimmering”.
Ms Ng, who is self-employed, noted no discernible change in temperature while observing the phenomenon from home, and said the light went away after a while.
Several comments on her post joked about how it might have been the handiwork of fictional characters such as Dr Strange – a character from Marvel – opening a portal in the sky, just like the orange portals he opens in the movies.
Others said, tongue in cheek, that the light pillar may be a sign of “the end of the world”.
Assistant Professor Wang Jingyu from the National Institute of Education told ST on Dec 13 that “the orange light alone does not necessarily indicate a cause for caution or alarm”. He noted similar events, like the orange flare that appeared over Texas on a night in March 2022, and said that “it is simply a wonder of nature”.
Prof Wang, who holds a PhD in atmospheric sciences, said such lights are usually a reflection of sunlight during sunset or surface flares at night against a specific shape of ice crystals in the atmosphere.
He said ice crystals can exist in nature in various forms, such as bullet rosettes, needles, plates and dendrites. “However, only plate-shaped ice crystals have the potential to generate this phenomenon,” he said.
Calling it an “extremely rare phenomenon in the sky”, he said it is highly possible that the light witnessed on Dec 10 was a reflection of flares originating from oil refineries in Johor.
“When a substantial number of these plate-shaped crystals are present in the atmosphere, they act like a colossal mirror, (perfectly aligned at a height to be) reflecting light,” he said.
