An explosion at an electrical power station in New York City on Thursday evening has caused the lit up the sky with an eerie blue light – and triggered a flurry of speculation on social media.
Some netizens are wondered if aliens had landed.
Others says something supernatural might be to blame for the ghostly glow.
But their guesses were all wrong, as New York Police took social media to explain the phenomenon.
The New York Police Department (NYPD) reassure the public that the strange light was caused by something much more down to earth – a transformer explosion at a Con Edison power station in the Astoria neighbourhood of the borough of Queens.
The blue colour comes from the way electricity passes though air.
Electrical energy will knock electrons off atoms in the gases that make up the air.
When these electrons recombine with the excited atoms, returning them to their starting energy state, light is emitted.
The colour of the light emitted depends on the type of atoms involved.
Furthermore, A blue colour is associated with oxygen atoms; pink/purple colours are associated with nitrogen atoms. Oxygen and nitrogen are the gases that dominate the air we breathe.