UPDATE: The purple glow appears to be from a local Langley greenhouse that is testing out some new technology.
WATCH: Our Global crew appears to have found the answer to the mysterious purple sky over parts of Metro Vancouver and the Fraser Valley last night.
Residents of Langley and the Fraser Valley may have noticed something unusual in the sky on Wednesday night – a purple glow.
Social media users started posting images of the sky online, showing a bright purple glow in an otherwise dark sky.
On the Global BC Facebook page, some users say the light comes from a greenhouse in Langley or Chilliwack.
Check out this photo:
But others, who have lived in the area for years, were surprised to see such a vibrant light above their homes.
Environment Canada says the light could have been created by a rare atmospheric phenomenon.
Particles in the atmosphere, such as dust, salt and soot, are called aerosols. The purple light was seen after sunset and is created by a break in the clouds.
The purple light is rare because there were breaks in the low cloud (probably over the Georgia Strait), but the upper atmosphere had completely cleared, meaning it cleared a path for the red light from the sunset to interact with aerosols higher in the atmosphere where the sky was still blue.
The red light plus the blue light equals purple.
So what do you think it was?