A greenhouse!
I know, but bear with me. Many on Twitter / Instagram snapped photos of similar lights, in recent times and in various places, and one of the sources was tracked down:
It turns out the mystery light came from a new, high-tech,
85,000-square-foot greenhouse on 76th Street near Hanna Lake Avenue
southwest of Dutton. The glow was the result of special purple LED
lights that can adjust to different spectrums to fit plants’ needs.
Sources:
It’s been reported in several places around the USA and Australia, and so far at least, always comes from greenhouses with these LEDs.
Credit:stackoverflow.com‘