Last night @astrokiwi.bsky.social showed me that you can actually see the Milky Way from inside the city of Christchurch! I did not expect that, and actually wasn't even planning get outside and look up, because I'm in a city. (Yes this is a couple-second-exposure, but you could definitely see it naked-eye.)
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@sundogplanets @astrokiwi.bsky.social
Hello darkness my old friend
The population of Regina, Saskatchewan is about 200k, Christchurch is 400k. Somehow, Regina has worse light pollution. I don't think the city is more concentrated, it's in the middle of the prairies, there's literally nothing to keep it from sprawling. (Is it just the snow on the ground? I don't know what time of year these measurements are taken.)
I'll have to do a bit more reading, but it's very interesting to me that NZ cities seem to be much darker than equivalent size Canadian cities.
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@sundogplanets Are those light pollution maps just for NZ or worldwide?
@sundogplanets Is that Regina or a Mandelbrot set?
@sundogplanets the colours in the center look the same to me? Blob looks bigger, or is that just a different scale?
My theory: trees!
I think snow reflection makes a huge difference. We got a dusting of snow the last couple of days (doesn't usually snow here) and last night the cluster of houses (and lights) on the hills across the valley were glowing very brightly. I was confused about what was happening but then I thought about the snow. Plausible theory?
@sundogplanets Queenstown is far smaller, but I stopped on my tracks getting out of a house or a restaurant there and seeing the Milky Way like you can’t really see it in Finnish countryside (at least in S/SW Finland).
@sundogplanets What are the streetlights like? Does one have covers, directing light down? Is the light colour temperature different?
@sundogplanets Quick look on GE: seems like Christchurch has more patches of parks and nature inside the city and i guess that decreases the light intensity.
@sundogplanets Snow is a great theory. I would also be curious about the age of the stock of streetlights in each city. Dark sky advocacy looks relatively well developed in NZ.
@sundogplanets @grb090423 The wind in Regina keeps pushing the outskirts towards downtown. That’s why it’s more concentrated.
@NunavutBirder Regina is the literal opposite of "concentrated". It is full of empty space, most of it paved.
I think the light pollution comes from the fact that no lights ever get turned off. It is as lit (and empty) at 2am as it is at any other time of day. Plus of course all the ginormous trucks with their extrabright lights.
(It may be obvious from the above, but I'm not a fan of Rjj.)
@transitionalaspect @sundogplanets @grb090423 I lived in Regina.
@NunavutBirder I think we're using different benchmarks for "concentrated". I'm a born European. For me, Rjj is unbelievably spread out. The width of the roads gets me every single time. And the parking lots!
But I see how this might be different from the Nunavut perspective... @sundogplanets @grb090423
@transitionalaspect @sundogplanets @grb090423 I was just attempting to make a joke about the wind in Regina. A weak attempt no doubt.
@NunavutBirder @grb090423 Best theory I've heard so far!
@sundogplanets Interesting. I hadn’t considered Christchurch skies particularly dark. Since we switched to LED lighting there’s been an eerie green glow across the city at night. Does Regina use LED street lights now too?
https://www.smartcitiesworld.net/news/news/smart-streetlights-save-christchurch-ratepayers-15m-6778
@sundogplanets
It makes such a difference what sort of street lights are used and especially where they're pointing. In Montreal, the newer lights only shine on a smallish area straight down, and it's much better than the old ones that blast light in every direction...!