[HN Gopher] Light Pollution Map
       ___________________________________________________________________
        
       Light Pollution Map
        
       Author : okl
       Score  : 326 points
       Date   : 2021-04-23 15:12 UTC (7 hours ago)
        
 (HTM) web link (www.lightpollutionmap.info)
 (TXT) w3m dump (www.lightpollutionmap.info)
        
       | ryandrake wrote:
       | It would be really great if this and other kinds of geospatial
       | data were more open and easily mashed-up. Let's say I wanted to
       | find a nice tract of land to buy (Zillow), which has good hiking
       | trails (AllTrails), low light pollution for stargazing
       | (lightpollutonmap.info), and maybe a dirt airstrip (vfrmaps) to
       | fly into. Currently, I have to have four browser windows open
       | with each site. There's no way to mash this data up easily
       | without reaching for the dev tools and hoping each site provides
       | raw data. Wouldn't it be better if everyone made data
       | accessibility a priority rather than just packaging it up for
       | each site's very narrow use case?
        
       | monocasa wrote:
       | The map around Denver seems questionable. Same falloff in the
       | plains to the east as in the high mountains directly to the west
       | doesn't match my experiences.
        
       | ravenstine wrote:
       | Does this tool take into account elevation? The Mt. Wilson
       | observatory, for instance, being on the outskirts of LA, is in a
       | red zone on that map, yet is still a great place to stargaze.
       | 
       | Not that this map isn't useful and insightful, but perhaps it can
       | make things seem worse than they really are? As long as you have
       | mountains around you, it's not like you can't go there to see the
       | stars with the naked eye. Last year, that comet was pretty easy
       | to see from up there.
        
         | tppiotrowski wrote:
         | I've camped around the Los Angles area and it is visibly bright
         | in the mountains up to 50 miles away to the point that it feels
         | like twilight on the horizon all night long.
        
         | krneki wrote:
         | World Atlas 2015 model accounts for elevation. So locations
         | with higher elevation are darker. But it doesn't account for
         | obstacles like a mountain range shielding you from a city
         | behind it.
        
         | sparker72678 wrote:
         | You've gotta get out to a truly Dark site -- sounds like you'd
         | love it.
        
       | jumaro wrote:
       | I really like that site. Have used it multiple times to find dark
       | spots for photographing the milky way. However, I don't
       | understand why the default overlay is from 2015, when there is
       | newer data available. First thing I usually do is switching to
       | the most recent overlay.
        
         | krneki wrote:
         | There are VIIRS maps and World Atlas 2015 map. They show
         | fundamentally different things. VIIRS shows you sources of
         | light pollution while World Atlas shows you how these sources
         | of light impact the sky above you.
        
           | jumaro wrote:
           | Thanks for the explanation!
        
       | [deleted]
        
       | oliwarner wrote:
       | What's the deal with Belgium? It's lit up like a stadium.
        
         | Dries007 wrote:
         | We had a legal requirement for street lamps everywhere until a
         | few years ago.
        
       | airstrike wrote:
       | Very interesting to contrast developed nations with developing
       | ones, as usual. From this map, Brazil looks like a great country
       | to stargaze from.
        
       | [deleted]
        
       | jonah-archive wrote:
       | This is a bit tangential, but should be a pretty good aurora over
       | North America tomorrow (Sat Apr 24) night -- visible on the
       | horizon as far south as Salem, OR to Annapolis, MD:
       | https://www.gi.alaska.edu/monitors/aurora-forecast
       | 
       | (forecast is for the UTC day, so the prior overnight for NA)
        
         | slowhand09 wrote:
         | I live in Annapolis. I can't determine from the link how to
         | tell if its projected to be visible there.
        
         | jakear wrote:
         | Neat! Any idea where on the Oregon coast would be the best
         | place to watch? Hard to tell specifics from that map.
        
           | jakear wrote:
           | Answered my own question with the power of macOS preview. So
           | the center of the outer band lies at around Newport, then
           | continues to just south of Bend.
           | 
           | Cross referencing with the dark sky map, your best bet on the
           | coast is probably around Roosevelt Beach, though the Oregon
           | Dunes and Dismal Swamp general area also holds promise
           | 
           | (I have no idea how far out of the band you can be while
           | still seeing it, they list Salem as a good viewing spot,
           | which is much further north than the band)
        
         | slowhand09 wrote:
         | I live in Maryland. I can't determine from the link how to tell
         | if its projected to be visible there.
        
       | exhilaration wrote:
       | It looks like this site is more up to date but there's also Dark
       | Site Finder, which is usually what I've seen suggested in
       | stargazing discussion: https://darksitefinder.com/maps/world.html
        
       | intrasight wrote:
       | I didn't realize that the Susquehannock State Park was such a
       | dark place.
        
       | JoeAltmaier wrote:
       | Is it a rendering artifact or something, that the left half of
       | the United States is entirely darker than the right half? Like a
       | line was drawn down the middle.
        
         | Zircom wrote:
         | Nope, just that the western US is less densely populated than
         | the eastern side of the country and that is directly reflected
         | in the amount of light pollution.
        
         | lolinder wrote:
         | Nope, if you look at a population density map it has the same
         | line. I'm not at all sure why that's true, geographically.
        
           | mahogany wrote:
           | I think that's roughly the beginning of the Great Plains. I
           | would guess the population density drops significantly
           | because of farmland and ranching.
        
             | lolinder wrote:
             | Yeah, that seems right, but it's bizarre how straight up-
             | and-down it is. I can see why GP thought that it looked
             | artificial.
        
         | davidcuddeback wrote:
         | No.
         | 
         | https://media.sciencephoto.com/image/c0249398/800wm/C0249398...
        
       | ransom1538 wrote:
       | I can still smell the diesel oil cars of Madrid. Are diesel cars
       | super popular in EU?
        
       | geijoenr wrote:
       | Is amazing the amount of light pollution in Siberia around the
       | oil/gas extraction areas.
        
         | bigthymer wrote:
         | Is that the area north of Kazakhstan? That's a lot of light if
         | so.
        
       | titzer wrote:
       | I am grateful for this map. I used it to scout out Mojave desert
       | as a place to do some stargazing. I was surprised that Las Vegas
       | is still very clearly visible on the horizon, despite this being
       | a very dark "hole" in the map.
       | 
       | You gotta go _really_ far out to get dark skies all the way to
       | the horizon.
        
         | dheera wrote:
         | If you don't require dark skies for 360 degrees, you can get
         | away with going to a place that has dark sky in the direction
         | of whatever you're trying to observe.
         | 
         | I've done a lot of deep sky photography within an hour of the
         | Bay Area by being mindful of this.
        
       | davidw wrote:
       | Behold, SE Oregon:
       | https://www.lightpollutionmap.info/#zoom=7.67&lat=43.0350&lo...
       | 
       | One of the best places in the country for dark, clear skies.
        
         | rootusrootus wrote:
         | I'd like to get out there sometime. Even class 2 is really good
         | for me, so we drive one once or twice a year and camp at brooks
         | memorial state park north of goldendale. Easy to reach, has
         | amenities nearby, still very dark. It has a good
         | convenience/dark ratio for people coming from Portland.
        
       | giarc wrote:
       | I was looking at North America as a whole, and noticed a very
       | bright spot in Prudhoe Bay in Alaska. It's almost one of the
       | biggest spots. Wikipedia tells me it has a population of
       | basically 2000 people. Why is it so light?
        
         | stormbrew wrote:
         | Go a little farther south and find Ft McMurray in Alberta,
         | which isn't even traditional oil fields but oilsands
         | excavation. Only about 70k people but it's basically as bright
         | as the 1m people cities to the south of it (and the extra wide
         | halo around Edmonton is likely related to refineries).
         | 
         | Heavy industry is bright I guess.
        
         | steanne wrote:
         | "...however, at any given time, several thousand transient
         | workers support the Prudhoe Bay oil field."
        
           | giarc wrote:
           | The bright spot is bigger than the bright spot over Paris and
           | London though. Do they just leave the lights on 24/7 in the
           | bay?
        
             | ewhanley wrote:
             | Prudhoe is a massive oilfield. It's thousands of wells
             | spread covering an area around 200k acres. Every well pad
             | and facility has lighting.
             | 
             | Oilfields operate 24/7 so the lights are always on. Of
             | course there's ~24 hours of daylight for half the year on
             | the North Slope and ~24 hours of darkness in winter.
        
             | afterburner wrote:
             | Oil installations are extremely well lit.
        
             | lifeformed wrote:
             | Oil flares.
        
         | Pyrodogg wrote:
         | Oil industry. Same reason western North Dakota looks like a
         | major metropolitan area.
        
           | toddsiegel wrote:
           | I saw this same thing.
           | 
           | https://www.npr.org/sections/krulwich/2013/01/16/169511949/a.
           | ..
        
             | Scottopherson wrote:
             | "Many farmers in North Dakota can't prevent drillers from
             | drilling -- even if they'd like to. Decades ago, the rights
             | to the minerals below those farms were separated from the
             | rights to the land itself -- which is why today, energy
             | companies can move in, create drilling pads where they
             | please, move in trucks and workers, without the farmers'
             | consent."
             | 
             | Am I reading this right? A company can just plop drilling
             | operations on a farmer's land?
        
               | ewhanley wrote:
               | That's right. You can't prevent a mineral rights holder
               | from accessing their resources - even if you hold the
               | surface rights. The company developing the minerals has
               | to compensate the surface owner for roads/pads/etc.
        
         | exhilaration wrote:
         | Oilfield flaring, Google has videos:
         | https://www.google.com/search?q=Prudhoe+Bay+gas+flaring
        
       | dgemm wrote:
       | Most of this seems pretty explainable except for the offshore
       | spots near South Korea, both east of Busan and near Jeju. Fishing
       | related?
        
         | koboll wrote:
         | Oil rigs?
        
         | steanne wrote:
         | https://earthobservatory.nasa.gov/images/79796/korea-and-the...
        
       | abhayhegde wrote:
       | This has been a very useful website. I observed that the more
       | "developed" a place is, more the population and inevitably a lot
       | of light pollution. I wonder how to reduce light pollution while
       | not bargaining with the safety at night.
        
         | giantg2 wrote:
         | Give everyone night vision?
        
       | wishinghand wrote:
       | I'm really surprised how polluted some parts of the USA are, like
       | North Dakota. I would have figured there'd not be much there.
        
         | datagram wrote:
         | Apparently it's due to fracking. Here's an article I found
         | about it:
         | https://www.npr.org/sections/krulwich/2013/01/16/169511949/a...
        
         | holub008 wrote:
         | I was surprised by North Dakota as well. I believe that bright
         | spot corresponds to oil fields.
         | 
         | https://en.wikipedia.org/wiki/Bakken_Formation
        
       | mygoodaccount wrote:
       | The site appears to be using OpenStreetMaps based on the font.
       | But I don't see any attribution to OSM anywhere on the site? It's
       | a part of the agreement to use OSM...
       | 
       | *I was wrong
        
         | nattaylor wrote:
         | It uses Bing Maps and has this:
         | 
         | (c) 2021 Microsoft CorporationEarthstar Geographics SIO(c) 2021
         | TomTomTerms of Use
         | 
         | Jurij Stare, www.lightpollutionmap.info (v2.7.7) VIIRS Earth
         | Observation Group, NOAA National Geophysical Data Center
        
           | tppiotrowski wrote:
           | Are you using a framework for your map or did you come up
           | with those tooltip dissolving into tic-tac-toe animations
           | yourself?
        
             | nattaylor wrote:
             | Typo corrected. I am not the creator and meant to write "It
             | uses"
        
       | jFriedensreich wrote:
       | i totally get that we should save energy and make areas great for
       | astronomers as well as give insects and birds plenty room to not
       | be disturbed by light. BUT living in a german city is just
       | depressing at night. you can barely see at a lot of places and
       | its just inconvenient to walk, also everything possible is
       | closed, there are no big 24h shops (like asda or geant, i dont
       | mean spatshops for snacks) or anything urban or exciting i would
       | expect in a modern city.also a lot of places have these dim and
       | yellow orange depressing lights instead of more daylight like
       | modern leds. can someone explain how this is a good thing?
        
       | unbalancedevh wrote:
       | This is kind of depressing. I'm looking for a piece of land where
       | I can get away from light pollution, and this is telling me that
       | there is no such place anywhere near me, even out in the
       | "countryside."
        
         | foobiekr wrote:
         | Same. I would like to move to somewhere with low light
         | pollution but isn't far from good medical care. Impossible, at
         | least in the US.
        
         | xattt wrote:
         | The eastern end of Prince Edward Island (Canada) comes pretty
         | darn close to this darkness. Even though it's sparsely
         | populated, it's a place that doesn't feel isolated because of
         | social capital.
        
       | Black101 wrote:
       | Wow I am surprised that Atlanta has so much light...
       | 
       | This map appears to be pretty close to this image:
       | https://www.nasa.gov/sites/default/files/images/712129main_8...
        
       | rebuilder wrote:
       | I checked the area I live in, it's pretty rural and has no red,
       | except for one blob that seems to be in the middle of nowhere. So
       | I looked it up on a satellite photo and sure enough, there's a
       | large greenhouse operation there.
       | 
       | Seems odd that they'd be running their lights at night, though.
        
         | dubcanada wrote:
         | Depends on what they are growing, cacti and orchids for example
         | LOVE 24/7 light and grow way faster then the typical 16/8 light
         | schedule.
         | 
         | But most are probably some form of veggie or flower so they
         | need 16/8 light schedule.
        
       | the_arun wrote:
       | Isn't Light Pollution directly proportional to population
       | density?
        
         | ehsankia wrote:
         | In general yes, though just looking quickly, it seems like
         | Belgium for example was a lot brighter than surrounding
         | countries, and I don't think they have that high of a density?
         | 
         | I would liked to see a map like this normalized for population
         | density, though not sure how granular that data is.
        
         | bena wrote:
         | Looking at the US map, it seems to be.
        
       | tppiotrowski wrote:
       | Nice project! A few questions:
       | 
       | How is this data collected? (I'm guessing a satellite image of
       | city lights across the world)
       | 
       | I'm trying to understand the scale. Zenith means overhead, so
       | overhead sky brightness. The magnitude scale stops at 17 but I
       | thought magnitudes above 7 is no longer visible to the human eye
       | [1]
       | 
       | [1] https://en.wikipedia.org/wiki/Apparent_magnitude
        
         | bttrfl wrote:
         | this is explained in the FAQ. They merge different sources,
         | notably data from SQMs which "stands for Sky Quality Meter.
         | It's a small device that can measure sky quality ie. darkness.
         | It's widely used by amateur astronomers because it's fairly
         | cheap and gives you fast results which can be easily compared
         | to other SQM users."
         | 
         | https://www.lightpollutionmap.info/help.html
        
         | [deleted]
        
       | agys wrote:
       | We proposed - as a counter-point to the many "light-festivals" -
       | a festival of darkness: all the lights of the city would be off
       | for one night. It didn't get trough, unfortunately.
        
       | baltimore wrote:
       | This place in Kazakhstan is lit!
       | https://www.lightpollutionmap.info/#zoom=5.62&lat=48.7573&lo...
        
         | afterburner wrote:
         | Check out this spot in northern Siberia:
         | 
         | https://www.lightpollutionmap.info/#zoom=5.58&lat=67.9757&lo...
        
           | iguessthislldo wrote:
           | I was drawn to that same spot because it was big but there's
           | no city there on the map. I opened google map to see what was
           | there and found this: https://www.google.com/maps/place/Vanko
           | r+manufacturing+site/...
           | 
           | Seems to be an oil field:
           | https://en.wikipedia.org/wiki/Vankor_Field
           | 
           | Also didn't google it as much, but it looks like oil fields
           | in Texas give off plenty of light as well: https://www.lightp
           | ollutionmap.info/#zoom=9.14&lat=28.6928&lo...
        
             | shuntress wrote:
             | I was looking at this same spot.
             | 
             | People have uploaded some great pictures from there[0]!
             | 
             | [0] https://www.google.com/maps/place/Vankor+manufacturing+
             | site/...
        
         | baltimore wrote:
         | Oil field or something?
         | https://www.google.com/maps/place/48%C2%B014'12.6%22N+57%C2%...
        
           | hbosch wrote:
           | I assume it must be. The incredibly bright spots at Keene,
           | North Dakota and the northern edge of Alaska have similar low
           | population/bright spots.
        
             | s1mon wrote:
             | Seems like the right answer. I was looking around on some
             | maps until I found things marked SWD - which is Salt Water
             | Disposal. Apparently the "safe" way to dispose of the used
             | fluids from fracking.
             | 
             | https://www.google.com/maps/search/swd+north+dakota/@47.669
             | 0...
        
       | 2iP1zbR wrote:
       | i remember a long time ago i was told north korea was a dark spot
       | on earth when viewed from space, interesting to see it on an
       | actual light pollution map. not that north korea is alone in this
       | aspect.
        
       | Forbo wrote:
       | My state designated a Dark Sky Park in an area that's Bortle
       | class 4. Is the designation really that flawed? That's a shame, I
       | was hoping to some decent stargazing in without having to drive
       | for hours on end. Alas.
       | 
       | Edit: Looks like these are the criteria the IDA use.
       | https://www.darksky.org/wp-content/uploads/2018/12/IDSP-Guid...
        
       | mvexel wrote:
       | The data from the International Dark-Sky Association[0] would be
       | a good complement to this.
       | 
       | In case you're interested what a dark sky town ordinance looks
       | like for a small town that has the designation near where I live,
       | see here[1].
       | 
       | [0] https://www.darksky.org/our-work/conservation/idsp/finder/
       | [1]
       | https://codelibrary.amlegal.com/codes/torreyut/latest/torrey...
        
         | dheera wrote:
         | Ironically, it's not very international. 22 out of the 29
         | "International" Dark Sky Communities are in the US:
         | 
         | https://www.darksky.org/our-work/conservation/idsp/communiti...
         | 
         | I can think of a lot of towns outside the US that have
         | excellent dark skies but they aren't listed here.
        
           | bchanudet wrote:
           | Dark Sky communities are only one kind of designations, there
           | are also Dark Sky "Parks" [0], "Reserves" [1], and
           | "Sanctuaries" [2]. Those are much more scattered through the
           | world.
           | 
           | [0] https://www.darksky.org/our-work/conservation/idsp/parks/
           | 
           | [1] https://www.darksky.org/our-
           | work/conservation/idsp/reserves/
           | 
           | [2] https://www.darksky.org/our-
           | work/conservation/idsp/sanctuari...
        
             | dheera wrote:
             | It still looks _very_ US-biased.
             | 
             | I can think of several dozen places and parks in northern
             | Scandinavia, western China, Mongolia, Canada that are
             | almost devoid of light pollution that aren't even on this
             | list.
             | 
             | Also almost the entire country of Iceland and all of its
             | parks are excellent dark sky and not even mentioned here.
             | 
             | And that's just places I have personally been. I'm sure
             | there are huge parts of Africa, Australia and the Middle
             | East, and South America are excellent as well, and one
             | would think that if I were to travel to those continents
             | that I could look to a website called the "International"
             | Dark Sky Association to find out where the best dark sky
             | parks are in those places. But no.
             | 
             | It just seems a bit hypocritical to me to call it
             | "International" but with very little attention to the
             | wealth of excellent dark sky areas outside the US.
        
               | bchanudet wrote:
               | Oh yeah I do agree that it's still very US-centered and a
               | tad hypocritical.
               | 
               | I'd say it's mostly because there is an application
               | process. Unlike for example travel guides where people go
               | around the world to discover new places, IDA is waiting
               | for those places to apply. If you add the language
               | barrier, the quite long list of requirements and
               | political actions to make to be able to apply, that only
               | reduces the list of candidates.
               | 
               | I suppose there are also less-known local initiatives
               | throughout the world. Here in France, we have the ANPCEN
               | [0], fighting against light pollution and delivering
               | labels to cities that take actions against light
               | pollution (like shutting off the streetlights from 11PM
               | to 5AM).
               | 
               | [0] https://www.anpcen.fr/?id_rub=19&rub=participez-%E0-v
               | illes-e... (in French, but there is a Google Translate
               | button in the footer)
        
               | steanne wrote:
               | they give attention to the places that apply for the
               | designations.
        
       | anonymfus wrote:
       | I like this. I think it would be also useful to add isolines for
       | brightness of various astronomical objects to the map. I want to
       | easily understand where I need to go to see Milky Way for
       | example.
        
         | [deleted]
        
       | mig39 wrote:
       | Is the light pollution in the North Sea really that intense? How
       | about the Grand Banks off Atlantic Canada / Newfoundland?
       | 
       | Are these due to oil platforms?
       | 
       | I find it hard to believe that the light pollution at the head of
       | the Grand Banks, almost 200km off shore, is equivalent to the the
       | metro area of St. John's, nearby.
        
         | birktj wrote:
         | The North Sea ones are oil platforms, yes. I believe the light
         | intensity is largely because of gas flares [1], but I might be
         | wrong.
         | 
         | [1]: https://en.wikipedia.org/wiki/Gas_flare
        
           | afterburner wrote:
           | It's probably just because oil installations tend to be very
           | well lit, probably for safety.
        
           | nemacol wrote:
           | https://en.wikipedia.org/wiki/Hibernia_oil_field
           | 
           | Just found this as I was attempting to figure out what the
           | bright light is off Newfoundland.
        
         | cozzyd wrote:
         | Yeah, the oil fields seem insanely bright relative to cities. I
         | wonder if this has something to do with the sensor spectral
         | sensitivity or something...
        
       | supernova87a wrote:
       | I'm curious to know when the growing number satellites passing
       | through your sky become a bigger problem than the light
       | pollution?
       | 
       | Although, it is a qualitatively different kind of "noise" --
       | sparkly bright dots that fly through the dark sky periodically,
       | versus a glow that permeates the whole sky.
        
       | tut-urut-utut wrote:
       | It's not like nothing can be done about light pollution. For
       | example Germany has a law about light pollution, and it shows on
       | this map. It less polluted than its neighbours, although it has
       | higher population density and urbanization level.
        
         | crazygringo wrote:
         | Germany doesn't seem appreciably better than France, looking at
         | the map.
         | 
         | Peak levels are the same for Berlin as for Paris. The _width_
         | of Paris 's light pollution is wider, but it's also double the
         | population of the metropolitan area.
         | 
         | And actually, rural areas of Germany seem consistently and
         | significantly _brighter_ (worse) than rural areas in France,
         | across both countries.
         | 
         |  _Is_ there really a lot that can be done about light
         | pollution? Isn 't it mostly due to streetlights, which you want
         | on for safety?
         | 
         | I mean, sure there are some metropolitan downtown areas with
         | bright lighting of advertising, but that's very localized.
         | 
         | Is there really low-hanging fruit that cut could overall light
         | pollution by, say, 50%, without impacting safety?
        
         | throw0101a wrote:
         | The International Dark Sky Association has some template laws
         | that can be used as a starting point:
         | 
         | > _The MLO offers several innovations to outdoor lighting
         | regulation, including the use of lighting zones to classify
         | land use with appropriate lighting levels for each. The MLO
         | also makes use of the "BUG" (Backlight, Uplight and Glare)
         | classification of outdoor lighting fixtures to ensure that only
         | well-shielded fixtures are used._
         | 
         | * https://www.darksky.org/our-work/lighting/public-
         | policy/mode...
        
         | obviouslynotme wrote:
         | I would vote for anyone who would even talk about light
         | pollution as a serious issue. All my friends (rightly) think I
         | am a wacko because I advocate the removal of all streetlights
         | and regulation of private outdoor lights.
        
         | at_a_remove wrote:
         | Lord knows if I were emperor or whatever, I would have some
         | fairly draconian laws on the books, with hefty fines, about so
         | many light sources. I can walk around at night and read a paper
         | books. It's easy. Some places, I feel like the going standard
         | is "can someone perform open heart surgery on this stretch of
         | road?"
         | 
         | A lot of it is a race to the bottom -- look at my sign! Sure,
         | my business is not open right now, but I have a sign!
         | Advertising alone is a huge detriment to the light pollution
         | landscape.
         | 
         | Much of it comes from misguided "this will be safer" concerns.
         | And so half the neighborhood has these floodlights installed
         | above their doors that will be on all night, plus little solar
         | lights everywhere. Oftentimes, they're positioned so poorly
         | that it actually makes seeing people walking around _more_
         | difficult, due to having these things shine away in my eyes.
        
           | rootusrootus wrote:
           | One of my particularly patriotic neighbors has a big US flag
           | atop a pole in his front yard. And he's following flag code,
           | making sure that since he leaves it up at night it is
           | properly lit. With a couple great big floodlights aimed
           | straight up at it from the ground.
        
         | sparker72678 wrote:
         | https://www.lightpollutionmap.info/#zoom=7.00&lat=34.1123&lo...
         | 
         | Flagstaff vs. Prescott in Arizona is another good example.
         | Flagstaff has strict output per area limits, Prescott has none,
         | while the density of both areas is similar.
        
           | [deleted]
        
           | teslabox wrote:
           | Flagstaff makes an effort to enforce their lighting
           | ordinances, Prescott makes no effort whatsoever.
           | 
           | I think the problem is that all the people who knew why the
           | lighting ordinances were passed retired. Because Prescott
           | doesn't have Lowell Observatory in the city limits the
           | reasons behind the ordinances were forgotten.
           | 
           | Blue-white outdoor lighting should be prosecuted as a public
           | nuisance.
        
           | jjtheblunt wrote:
           | Cave Creek Arizona is another dark sky area (where we live)
           | and it's an excellent thing
        
         | Naac wrote:
         | What is the law? What are people legally required to do?
        
           | dheera wrote:
           | Most light pollution laws limit outdoor lighting fixtures and
           | require them to only emit downwards and not upwards.
        
           | wongarsu wrote:
           | Probably the most noticable change in recent years is the
           | replacement of mercury-vapor streetlights with the yellow-
           | orange sodium-vapor lights, or with orangish LEDs (although
           | some use blueish LEDs that are not that great for light
           | pollution).
           | 
           | In terms of actual legal requirements, Bavaria prohibits sky
           | beams/searchlights directed upwards, and the illumination of
           | facades of public buildings between 11pm and morning.
        
             | acwan93 wrote:
             | San Jose, California does this for the Lick Observatory at
             | Mt. Hamilton, although I think they're switching to blueish
             | LEDs. The sodium-vapor lights are frequently mistaken as
             | yellow traffic lights though, in my experience.
        
             | NavinF wrote:
             | yellow-orange sodium-vapor lights are terrible for anyone
             | who's not an astronomer. The sharp output spectrum prevents
             | humans from seeing color
        
             | terramex wrote:
             | While switching to LEDs can improve naked eye view of night
             | sky, it sometimes negatively impact amateur
             | astrophotography as mercury and especially sodium lamps
             | have narrow emission spectrum and it can be filtered off
             | using optical bandpass filters. LEDs light have much wider
             | spectrum and cannot be filtered off.
        
           | tut-urut-utut wrote:
           | Actually, I stand corrected, there's no federal German law
           | about light pollution. It's left to different federal states,
           | and most of them incorporated regulations about light in
           | their legislation.
           | 
           | I can't find an English text but the document from the
           | federal parliament below summarizes the legal state of the
           | topic in Germany.
           | 
           | https://www.bundestag.de/resource/blob/632966/7ba7c4cd1cfef8.
           | ..
        
       | jagged-chisel wrote:
       | Is this not just a population map?
       | 
       | https://m.xkcd.com/1138/
        
         | clutch89 wrote:
         | Certainly not. See the other comments about light pollution
         | from heavy industries (oil, etc), and also countries with
         | lower-than-expected light pollution compared to their
         | population, due to laws (Germany)
        
         | steanne wrote:
         | mostly but not completely and the exceptions are interesting.
        
       | cheeaun wrote:
       | Question, how is the gradient heatmap thing implemented?
        
       | gfrangakis wrote:
       | What is this random spot with seemingly nothing around it in
       | Russia?
       | 
       | https://www.lightpollutionmap.info/#zoom=5.85&lat=68.2729&lo...
        
         | aportnoy wrote:
         | APG flaring of the Vankor field?
         | https://en.wikipedia.org/wiki/Vankor_Field
        
         | ebertx wrote:
         | There are a lot of strange spots in Russia. I was looking at a
         | spot south of the Pechora Sea on the light pollution map, then
         | comparing it with Google Maps/Earth. I can't see anything that
         | would correlate with that much light.
         | 
         | https://www.lightpollutionmap.info/#zoom=6.17&lat=67.1945&lo...
        
       | davidbrent wrote:
       | I love this sort of thing, but like many heatmaps, I wish it had
       | a color blind toggle.
        
       | holoduke wrote:
       | It's probably similar to a map showing where most rich people are
       | living.
        
         | gibspaulding wrote:
         | I was thinking that too, and was fully expecting the top
         | comment to be a joke about heat maps that are actually
         | population maps, but it turns out there are some interesting
         | insights I wouldn't have expected. Namely that there are
         | substantial differences when comparing areas with light
         | pollution legislation with similar unregulated areas; also
         | interesting to see how much light pollution there is even at
         | sea!
        
       | korethr wrote:
       | Is it just me, or does his look quite a lot like a population
       | density heat-map? XKCD 1138[1] comes to mind.
       | 
       | For those persons concerned solely about light polution, this is
       | definitely useful. But another thing I think would be interesting
       | is this map, corrected for population density. Mentioned down
       | thread is that different localities have different rules
       | affecting lighting, and that this can be seen in the map.
       | Correcting this map for population density would probably show
       | that even more.
       | 
       | 1. https://xkcd.com/1138/
        
       | [deleted]
        
       | ianbooker wrote:
       | Every time I am on a motorway in Belgium I wonder why they have
       | such a huge amount of streetlights on highways. Maybe because it
       | doesn't matter anymore in terms of light pollution? :D
        
         | seszett wrote:
         | There's actually an explanation for this.
         | 
         | At first, it was intended to basically burn the excess
         | electricity produced at night by the first generation of
         | nuclear power plants in Belgium, at a time when it was
         | difficult to reduce their power output on demand.
         | 
         | From then on, because highways were always lightened up it was
         | unnecessary to use reflective paint and signage on the
         | highways.
         | 
         | And today, we're left with signage and paint that are difficult
         | to read at night unless the highways are lined with
         | streetlights, which makes streetlights necessary even though
         | the power plants have been able to adapt to load for a long
         | time now. You can really notice it on the dark sections that do
         | exist, signage is actually difficult to see when in most other
         | countries reflective signage is almost easier to see at night
         | than by day.
         | 
         | Now the streetlights are being slowly turned off, some are
         | being replaced with LEDs, and some of the signage is being
         | updated to reflective, but I don't know if there's any official
         | roadmap to eventually arrive to dark highways with reflective
         | signage.
        
           | gregsadetsky wrote:
           | Very interesting! I remember seeing
           | https://www.nytimes.com/2017/12/12/world/europe/belgium-
           | elec...
           | 
           | That article seems to point to potentially larger conflicts
           | of interest:
           | 
           | The official explanation is that it helps road safety and
           | provides security. But critics doubt this and say the
           | phenomenon sheds light not only on Belgium's roads but also
           | on a mutually profitable relationship among its politicians,
           | electricity distributors and main energy supplier,
           | Electrabel.
        
       | rorykoehler wrote:
       | I find it fascinating that this also works as a wealth map
        
       | dmrotar wrote:
       | Resources like this (and as others have mentioned, Dark Site
       | Finder) are very useful for astrophotography, especially for a
       | hobbyist like myself. Many don't realize how relatively close
       | they live to areas with great nighttime viewing conditions.
       | 
       | For example, upstate New York has some great viewing locations,
       | so even if you live in NYC it's an easy weekend trip. Here's a
       | shot I took of the Milky Way taken from such a site (one of the
       | darker spots in the map):
       | https://www.lumathon.com/photo/_qTYviEhy/Colors-of-the-Milky...
       | 
       | Edit: a few more of my other shots of the night sky for anyone
       | interested, various locations, all of which were scouted using a
       | light pollution map like the one posted --
       | https://www.lumathon.com/dan/photos/tag/stars
        
         | agogdog wrote:
         | Many (like myself) also don't realize how far away they live
         | from areas with great nighttime viewing conditions (a 3-4 hour
         | drive for me).
         | 
         | :(
        
         | amoorthy wrote:
         | Wow amazing! I've been itching to show my kids the Milky Way. I
         | myself have only seen it once in New Zealand decades ago. What
         | is the minimum dark sky rating to be able to see it with the
         | naked eye?
         | 
         | I live in the Bay Area and I know there is Pigeon Point
         | Lighthouse which is a dark sky spot but I think it's often
         | cloudy. If anyone has better suggestions would be grateful to
         | hear those.
        
           | doubtfuluser wrote:
           | I once got nice shots from Mt Tam. You can hardly see it, but
           | with an ok camera doing long exposure you can get some nice
           | pictures - even being so close to SF
        
           | JoeAltmaier wrote:
           | Lick Observatory
        
           | shagie wrote:
           | I'd suggest taking a road trip and go out to Panamint Springs
           | outside of Death Valley. I forget if it was Zabriskie Point
           | or Father Crowley Vista Point when I was there... but I felt
           | that I could see _all_ the stars that night. There was a
           | distant glow to the east that was Vegas and another glow to
           | the south west that was LA.
           | 
           | This also has an advantage that it's dry and so you don't get
           | clouds as much.
           | 
           | Though, specifically for the Milky Way:
           | https://darksitefinder.com/how-to-see-the-milky-way/
        
             | tshaddox wrote:
             | We stayed 2 nights at the hotel there in Panamint Springs
             | back in December, and even right outside the cabins (and
             | nowhere near a new moon) the Milky Way was clearly visible
             | after letting your eyes adjust for a few minutes. This was
             | in the parking lot where there's no real attempt at
             | avoiding nearby light pollution.
        
           | mceachen wrote:
           | I don't think these maps take into account mountains.
           | 
           | There are rest stops on 280 (just south of 92) that (at least
           | used to) host telescope parties:
           | https://maps.app.goo.gl/vWEkH1bSvaUZKZHS8. You can definitely
           | see the Milky Way from there, but remember it'll take 30
           | minutes to acclimate your eyes: tell your kids to stay off
           | their phones (!). You're behind the San Andreas range to
           | block out a lot of the peninsula light pollution, and you've
           | got the coastal range holding back the fog (at least most of
           | the time). Less moon is (much) better, and use a satellite
           | tracker to have something else to watch out for.
        
             | krneki wrote:
             | World Atlas 2015 model accounts for elevation. So locations
             | with higher elevation are darker. But it doesn't account
             | for obstacles like a mountain range shielding you from a
             | city behind it.
        
           | dheera wrote:
           | Davenport is a slightly better bet weather-wise than Pigeon
           | Point, as due to the shape of the coastline and prevailing
           | winds the clouds usually get swept past it. But it still gets
           | cloudy from time to time there. Route 1 in general is a toss-
           | up.
           | 
           | If you live in South Bay, the hands-down best place IMO is
           | Pinnacles National Park. It's only 1.5 hours from San Jose,
           | and easily daytrippable.
           | 
           | If you don't want to go that far, try anywhere along the
           | Airline Highway, in the Paicines or Tres Pinos area (just get
           | away from streetlights; for example, Panoche Road is a very,
           | very dark road), Coyote Lake (shoreline is open for
           | stargazing 24 hours; pay with machine at entrance), Henry Coe
           | State Park, or anywhere along Mines Road but at least 15km
           | southeast of Livermore.
           | 
           | Also, if you're going for Milky Way viewing, do make sure you
           | know when and where the Milky Way is visible. The bright part
           | and galactic core are only visible very late at night now,
           | after 11pm or so, in the east direction. In mid-Summer the MW
           | will be in the sky all night. In autumn the MW will be in the
           | southwestern skies early at night and not visible late at
           | night.
           | 
           | At other times, such as in winter, the outer parts of the
           | Milky Way are in the sky, but you need much, much darker
           | skies to make anything of it, and it's hard to see without
           | long exposure photography. The winter side of the galaxy is
           | actually really beautiful if you do a long enough exposure
           | and all the signal processing necessary to get rid of noise.
        
           | snitzr wrote:
           | When I was at the Grand Canyon, I saw the milky way right
           | after the sun set and before the sky was fully dark.
           | 
           | I've also seen the milky way in West Virginia.
        
           | sciurus wrote:
           | Based on https://astrobackyard.com/the-bortle-scale/ I'm
           | guessing 3 or 2 to see it well.
        
         | lifeisstillgood wrote:
         | I thought that the Northern Hemisphere was basically pointing
         | away from the Galactic Centre, so shots like this were
         | basically only from South America or Australia etc.
         | 
         | Its - brilliant. Well done and thank you
         | 
         | But .. oh man .. the _whole_ of the UK is polluted :-( maybe a
         | few bits of one Scottish Loch are free.
        
           | davidcuddeback wrote:
           | > _I thought that the Northern Hemisphere was basically
           | pointing away from the Galactic Centre, so shots like this
           | were basically only from South America or Australia etc._
           | 
           | From 40N latitude one can see the sky as far south as -50deg
           | declination (50 degrees south of the celestial equator). It's
           | true that the galactic center is in the southern sky, but
           | it's still visible from the northern hemisphere. If you can
           | see Sagittarius (the teapot), you're looking in the direction
           | of the galactic center.
           | 
           | The GP's shot is representative of what one can expect from
           | about 40N. From the southern hemisphere, I've seen shots of
           | the milky way that span from horizon to horizon, so I do
           | think they have the better vantage point.
        
         | cpach wrote:
         | Great shot!
        
         | dheera wrote:
         | I do a lot of deep sky landscape photography
         | (https://instagram.com/dheeranet/) and dark skies are essential
         | to that. Most of these are taken from pretty dark spots on the
         | map in California.
         | 
         | Especially essential is planning for dark skies _in the
         | direction of_ whatever it is you are trying to shoot, which is
         | in some cases arguably _slightly_ more important than the dark
         | sky level of where you are standing. If a galaxy rises over a
         | city, it 's going to be hard to image even if you're far from
         | the city.
         | 
         | One of the tools I use the most is an app called "PlanIt Pro",
         | which gives you pretty much all the info you need, including
         | being able to show where in the sky various astronomical
         | objects are, their magnitude, a VR simulation of them with the
         | 3D topo map, and lots of other things. It also has a light
         | pollution map built-in, and can show you the position of the
         | Milky Way. I plan many of my shots with it. There's a free
         | version and I can't remember which features are omitted from
         | that but it's been worth every penny for me.
        
       | [deleted]
        
       | geenew wrote:
       | Neat to see the historical data in the VIIRS maps. The area
       | around Uttar Pradesh / Bihar really seems to have developed a lot
       | in the past 8 years, for example.
       | 
       | I'd love to see an animation of this.
        
       | sparker72678 wrote:
       | Still dreaming that someday we regard light pollution as the
       | pollutant that it really is, though tbh I have little hope.
       | 
       | 99% of the people I talk to about this basically wish we could
       | replicate daytime levels of light all around the clock. They want
       | even brighter streetlights, even more lights around the outside
       | of their homes, etc.
        
         | bob1029 wrote:
         | I wish we would also do the same thing with low frequency
         | sound.
        
       | bondolo wrote:
       | It was interesting to see that the timeline accurately reflects
       | the changeover from sodium vapor to LED street lighting in my
       | community. Still too much light, but better.
        
       | Xophmeister wrote:
       | What are all the blobs in the North Sea? Oil rigs?
        
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