Today on my way from Madison, WI, USA to Minneapolis, MN, USA on highway I94 I saw sky light up with violet color. Timestamp on my picture is at 6:48 PM. It's very strange. I do not think it was northern lights, too soon to hop on alien story. I know this could be due to some lights, but it was so bright and spread across such a large area, its stuck in my head. I am attaching pictures. Not very good quality as I was driving.

Let me know if you guys have any guesses. enter image description hereenter image description here


1 Answer 1


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.


It's been reported in several places around the USA and Australia, and so far at least, always comes from greenhouses with these LEDs.

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    See the final sentence, where I quoted from the last article which points out it's been noted in many places around the country
    – Mark Mayo
    Commented Dec 1, 2018 at 6:22
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    I think I was confused by your phrase "snapped photos of it". I made another edit to try to clarify further. Feel free to roll back if you don't like it. Commented Dec 1, 2018 at 6:31
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    I get an ‘access denied’ page on the third link (the whole site, actually) – locally restricted, or just server bugout? Commented Dec 1, 2018 at 11:05
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    Wow, the overall efficiency must be pretty bad if so much light is sent to the atmosphere. And as an amateur astronomer, I'd be really angry at such a disturbing light source. Commented Dec 1, 2018 at 13:03
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    @LightnessRacesinOrbit To clarify, I meant a restriction on the part of the site owners for EU users, possibly because of GDPR. They would not be the only site to do that.
    – Tim
    Commented Dec 1, 2018 at 20:46

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