
Dark Site Finder: tracking light pollution to find locations for stargazing - kibwen
http://darksitefinder.com/maps/world.html
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dylan604
I use this site frequently. Whenever I travel on assignment, I look up what
the seeing will be like in that area. This sight quickly lets me know what
kind of imagery will be possible. I then use other sites to get an actual
seeing forecast that includes info like temperature, expected cloud coverage,
wind speeds, moon phase, etc.

I recently visited Australia and New Zealand, and using this site I knew I was
in for a treat at night.

Here's an example from NZ from a location that is represented by the first
blue color after green:
[https://vimeo.com/246328898](https://vimeo.com/246328898)

Here's an example from Australia also in the same blue color on the map.
However, this one starts while the moon is below horizon, and continues until
the almost full moon gets pretty high in the sky to the point it looks like
day light: [https://vimeo.com/241600503](https://vimeo.com/241600503)

By comparison, here's a video where all of the footage was taken from a
totally dark sky area of the map:
[https://vimeo.com/157779663](https://vimeo.com/157779663) The difference from
blue to black on the map is pretty significant.

I am quite the fan of this site. I'm not sure on the status of the site
currently, but when I first started to use it, I believe the data was many
years old at the time. Based on that, you can pretty much assume that if it is
old data, then it will only have gotten brighter in any given area. Very few
places take light pollution into consideration with new development.

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euroclydon
Wait... Stars are visible during the day with time-lapsed photography?

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dylan604
To be clear, no, that was not taken during the day. In that one clip from
Australia, the light is 100% only from the nearly full moon. With a DSLR and a
long exposure, that light will completely light up the area to the point that
it looks like day light. The only thing to give away that it is not taken
during the day are the stars being visible and the smoothness of the water.
The smoothness of the water gives away the long exposure.

On a full moon in dark sky locations, it is possible to walk around without
the need of a flashlight. Of course, you need to give your eyes time to
adjust. It is definitely bright enough to cast shadows. I've even seen shadows
cast from the light of the Milky Way on new moon nights. It is hard to believe
how bright starlight can be.

~~~
dboreham
I live in a "dark blue" area per the map, with a ~1h drive to absolute black.
Mind you, I'm not sure I've noticed that much difference between my back yard
and deep in the middle of Yellowstone.

Anyway, the thing that surprised me about long exposure DSLR dark photography
is that you get pretty decent color rendition. For some reason I didn't expect
that. You can very clearly see the different color temperature of the stars in
Orion, and if you have a very dimly illuminated foreground as you mention, you
see it in accurate full color. I guess I didn't expect it because human eyes
don't register color in low light. DSLR sensors are doing it photon by photon
through the Bayer filter..

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jakecopp
[http://www.lightpollutionmap.info](http://www.lightpollutionmap.info) has
much higher resolution data, down to tens of metres. You can also choose the
dataset by year - choose the "VIIRS 2017 March" dataset for the best detail.
Data comes from the Visible Infrared Imaging Radiometer Suite (VIIRS)
satellite [1].

For example, with the extra resolution I managed to find a dark patch near the
train line in between Waterfall station and Helensburgh south of Sydney - the
darkest sky until you go far past Wollongong.

[1]:
[https://jointmission.gsfc.nasa.gov/viirs.html](https://jointmission.gsfc.nasa.gov/viirs.html)

~~~
rkagerer
Is there a reason they default to the 2015 dataset instead of the 2017
dataset? Is it more complete?

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codebook
It's been a really long time when I saw the milkyway in the urban area. I
don't expect I can see the milkyway in the city (maybe at the total
blackout?), but I hope to see it within 30min drive. Also, I hope to see more
nebular in my backyard w/ decent telecope, I only could see a few famous
nebular such as Orion, Omega, faint veils...

Too bad for little people to be able to see that amazing nightsky .

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look_lookatme
I love looking at sites like this. My favorite is:

[https://www.lightpollutionmap.info](https://www.lightpollutionmap.info)

One thing I've always been curious about is there are 3 points of brightness
off the coast of Newfoundland. Does anyone know what they are?

[https://www.lightpollutionmap.info/#zoom=6&lat=5811787&lon=-...](https://www.lightpollutionmap.info/#zoom=6&lat=5811787&lon=-5227188&layers=0BFFFTFFFF)

~~~
abirkill
From the location of those light sources, I suspect they are from drilling
rigs extracting oil from several large oil fields around the Grand Banks of
Newfoundland.

There's a map of the largest fields in this article:

[http://www.cbc.ca/news/canada/newfoundland-labrador/husky-
we...](http://www.cbc.ca/news/canada/newfoundland-labrador/husky-west-white-
rose-1.4135594)

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sizzzzlerz
I was on a boat crusing through the Galapagos Islands and went topside to look
at the southern skies. I've never been is so dark an area. The Southern Cross
and the Jewel Box appeared almost 3-dimensional and the Milky Way was visible
from horizon to horizon. It was the most amazing night of star watching I've
ever had.

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StavrosK
I was once on a beach in the southern part of Crete in Greece, many hundreds
of kilometers away from the nearest city. There was no moon, and when we
turned off the flashlights we could barely make each other out, but the sky
was full of stars. It was glorious.

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kibwen
This might just look like an alternative visualization of those composite
images of the Earth from space at night, but what's nifty about this is that
it purports to also show just how far from populated areas one would need to
travel in order to maximize darkness.

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gmiller123456
Not seeing that feature. Maybe it's somewhere on the website, but the linked
page seems to just be a visualization of the common light pollution map.

~~~
dylan604
The entire map is the light pollution. The key there at the top of the screen.
Find where you are, and look at what color the area is around you on the map.
From personal experience, if you're in a downtown metropolitan area that the
map shows as white, then you'll be lucky to make out Betelgeuse or Rigel in
Orion, Sirius would be visible, as well as Venus, Saturn and Jupiter. Anything
fainter than that will be difficult. Using binoculars will improve things
quite a bit though. As you start to get into the orange colors, all of the
stars in Orion would be visible. I have been able to make out the Milky Way in
yellow areas. In the blue areas, I can see the Milky Way quite clearly. In the
black areas, it takes me a bit of time to adjust to find Orion/Big Dipper/etc
because there are now so many stars visible that the very obvious
constellations are harder to see immediately.

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Tharkun
I live in the middle of the giant cancer of light pollution that is the
Netherlands/Belgium/Germany triangle. Most of Belgium is on the white-ochre
spectrum. There are no dark spots to speak of within any reasonable distance.
It's depressing.

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kirse
DarkSiteFinder is a great tool in addition to this website:

[http://cleardarksky.com/csk/](http://cleardarksky.com/csk/)

Ex: Sierra Vista, AZ:
[http://www.cleardarksky.com/c/SierraVistaAZkey.html?1](http://www.cleardarksky.com/c/SierraVistaAZkey.html?1)

Which uses various models to calculate night sky visibility. Avoiding light
pollution is only one part of the game.

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sharpercoder
You can see most large metropoles having a white core. In Rotterdam and The
Hague (Netherlands), this white core is _in between_.

Very interesting. I live on the southern outskirts of The Hague, Netherlands.
Between The Hague and De Nieuwe Waterweg is the Glass City [0] located, a
large area (~20x20km) with mainly greenhouses. These greenhouses use
artificial light to spur growth in plants, causing the white core in the light
pollution heatmap.

When I look out on my balcony to the south, the sky never turns dark. Only
when there is heavy rain clouds, the light from the greenhouses dims _a bit_.
The sky is always in an orang-y darkish glow.

[0]:
[https://translate.google.nl/translate?sl=auto&tl=en&js=y&pre...](https://translate.google.nl/translate?sl=auto&tl=en&js=y&prev=_t&hl=en&ie=UTF-8&u=https%3A%2F%2Fnl.wikipedia.org%2Fwiki%2FWestland_%28Nederlandse_streek%29&edit-
text=&act=url) (translated dutch wiki page, english page is only stub)

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stuaxo
There should be a movement to restore darkness.

Nightlife has completely changed, music gigs are extremely well lit, where
before you had a dark room and the musicians illuminated.

Old lights have been replaced one for one by much brighter LEDs.

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dylan604
There is a big push by dark sky advocates to have cities rethink their
lighting. Nobody really expects metropolitan areas to just suddenly go replace
existing lighting, but at least for new lighting installs to use dark sky
friendly lights. These just keep light shining where it's needed (shining
down) versus wasting energy by lighting upwards. Some cities are positively
responding, and considering this when replacing/updating lights.

The astronomy campus I frequent works closely with the local and county
government to replace lights to be more dark sky friendly as they are working
to be officially recognized as a dark sky location.

~~~
canoebuilder
_There is a big push by dark sky advocates to have cities rethink their
lighting._

Do you have any links for formal or informal organizations or individuals
working on this? thanks

~~~
dylan604
I saw that someone else provided links to good info. As an anecdotal piece of
evidence, I know that big box home improvement places like Home Depot have a
dark sky category in their outdoor lighting department. I was flabbergasted
the first time I saw that. I would love to see the affect of all homeowners
replacing light fixtures with these types of lights. As an example, in the
last video I linked earlier today, there are small lights on the horizon that
shine very brightly in the video clips. There's one light source in particular
that is a single lamp on a pole located on a ranch that is several miles away.
If you multiply that by the output of every lamp in a city, it doesn't take a
lot of imagination to quickly understand why we can't see the sky at night.

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guelo
I don't like the key on this map. The actual map has some kind of alpha
overlay that seems to go to fully transparent for the darkest parts, while the
key is 100% opaque black for the darkest parts. In parts of the map it's hard
to tell if you're in the darkest area. A hover info window would be helpful.

~~~
suneilp
Use the slider at the top right. It controls the overlay transparency. It's
not ideal but it works to identify the darkest parts.

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JepZ
Anybody knows why there is such a large area with light in nothern/central
russia?

~~~
dsjoerg
Came here to ask this. What the heck! Here it is:
[https://imgur.com/a/vXwqO](https://imgur.com/a/vXwqO)

EDIT: Never mind, apparently it's oil and gas refineries!
[https://www.reddit.com/r/answers/comments/4x0v1e/why_is_ther...](https://www.reddit.com/r/answers/comments/4x0v1e/why_is_there_so_much_light_pollution_in_northern/?st=jcwa6poj&sh=16c7073c)

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mmmrtl
You can see updated nightly images of what is presumably the source imagery
(Suomi NPP VIIRS) on NASA's satellite imagery viewer:

[https://worldview.earthdata.nasa.gov/?p=geographic&l=Referen...](https://worldview.earthdata.nasa.gov/?p=geographic&l=Reference_Features,VIIRS_SNPP_DayNightBand_ENCC)

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nsxwolf
Does the legend not match the actual colors used on the map, or is the entire
surface of the planet light polluted? I don't see a single area on the Earth
that's as dark as the three darkest colors on the legend.

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codingdave
The legend isn't a perfect match - there is an opacity on the color overlays
that makes the black side of the legends instead be lighter shades of grey
when on the map.

~~~
jacoblett
Sorry to reply on this thread but I wasn't sure how to contact you otherwise.
Thank you for your comments regarding my landing page copy. I think you are
right, and I was assuming my bad experiences were what others would
experience. I revised my page based on your feedback. So thanks.

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enobrev
I use this site when trying to find good places to go camping. When I moved
back to Chicago, I was pleasantly surprised to find a few decent stretches of
night sky within a 4 hour drive from the city.

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doodlebugging
I think this would be more useful if the color bar had a slider that tracked
the user's mouse across the map.

Also, where does the color bar information come from? Is it from observational
data of the dimmest magnitude stars or objects visible at a particular
location or is it just integrating data from satellite based night-time passes
to show light received on clear-sky passes?

Seems to be moderately useful but the actual utility of anything like this is
dependent on the source and processing of the data used to create it.

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larrydag
I like it but i want to know that the colors represent. For instance, what is
eliminated from view in the night sky because i'm in a white, red, or green
region.

~~~
dylan604
From personal experience using this map, if you're the worst areas designated
by white on the map, you will be able to make out only the brightest of
objects like Venus, Jupiter, Saturn, Rigel, Betelgeuse, Sirius. Anything
fainter will be difficult with the naked eye. As you get into the
reds/oranges, you'll be able to see most of the more visible constellations. I
can find all of Orion and the Big Dipper. In the yellow areas, the Pleiades
cluster is pretty visible. In the green areas, you might be able to make out a
faint shape of the Milky Way, but the time you're in a blue area you will
definitely see it. In the black areas, it's almost overwhelming how much can
be seen.

If you live in an area any where from red to white and are not usually prone
to looking up, then I'd venture a guess that you might be pretty impressed by
visiting a yellow to green spot on the map. Being bold and visiting a blue to
black area will just blow you away.

These are all naked eye examples. Using any type of seeing aide will improve
things dramatically. A simple pair of binoculars in a white part of the map
will reveal so many more stars. The entire constellation of Orion can be seen
in binocs. You just need a few visible starts to find your way. Any of the
apps like StarWalk or StarChart will help you find your way. However, in the
white parts of the map, I can never see Polaris bright enough to properly
align my telescope for accurate guiding. I usually just use my phone's compass
to point in the general direction of North, and go from there. In those areas,
I can easily see the rings of Saturn and a few moons, make out the belts on
Jupiter and several moons, and have even seen the different phases of Venus. I
even took the scope out to a roof top bar a few years ago to let people see
one of the PanStar comets.

~~~
planteen
It seems like there's another factor of altitude or maybe humidity that makes
a difference. In my experience, Atlanta is like you describe - a handful of
stars and planets. But in Denver, which is colored the same as Atlanta, I can
easily make out Orion for example this time of year.

~~~
dylan604
Altitude and humidity definitely play a factor in the seeing clarity. There's
a reason the really big telescopes are built on top of mountains. The thinner
the air, the less atmospheric distortion. The current favorite location for
observatories is the Atacama Desert in Chile. Extremely high altitude and
humidity in the 0%-1% range. I'd guess only Hubble gets better views.

Sea level beach locations are horrible for imaging with the ocean mist and
humidity. However, visually, watching the stars rise/sink into the horizon of
the ocean is one of my favorite sites for just watching. The power of ocean
waves and the enormous sky just helps put into perspective our place in the
universe.

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mlinksva
I wonder if
[http://www.darksky.org/idsp/communities/](http://www.darksky.org/idsp/communities/)
can be discerned on this map? I can't at a glance, but of course it'd be hard
to tell unless the difference were pretty stark and it's hard to tell what the
right comparisons are for a given community.

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sgt
What stood out for me; how divided the US is. And also (expectedly), how dark
North Korea is on this map in comparison to South Korea.

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floren
The Gila National Forest is a pretty good-sized dark blob on that map and it
truly is amazing. Midnight in March showed me an abundance of stars that I'd
forgotten even existed, having lived in cities for almost 15 years. The
massive fireball that lit up our campground so much we were able to turn
around in time to see it was just icing on the cake.

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squeaky-clean
I like this site:

[http://www.jshine.net/astronomy/dark_sky/](http://www.jshine.net/astronomy/dark_sky/)

The UI isn't as nice, but it has pins for recommended dark spots. I've found
several of my favorite stargazing spots this way.

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kallus
What is that big bright area, with some very bright spots, in Russia? North of
Kazakhstan.

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anonymfus
Gas flares. IIRC about half percent of world's CO2 emissions are from here.

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rmaus
This is a great resource for astrophotographers. I always check it prior to
traveling somewhere new (particularly the western US) to see if it's worth
packing equipment and taking a detour for photo opportunities.

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craftyguy
This is really useful, especially since you can view satellite images. Here in
the Pacific NW, just having clear dark skies is not enough.. you also need a
clear-cut on top of a hill!

~~~
dylan604
There's a popular spot north of LA where a lot of the amateur astronomy groups
meet up that sounds similar. It's the top of a mountain, but the viewing is
severely limited because of the height of all of the trees surrounding the
area, but it's the only/best place within a 90 minute drive of downtown LA.
Beautiful drive up to the location too.

~~~
maxxxxx
I guess that's Mount Pinos. You can go a little further north from there into
the desert and it's really dark there to see the whole Milky Way across the
sky.

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dawnerd
Ojai used to be that way when I was growing up. Normal summer night could see
so much.

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pradn
I was shocked to be able to see Orion quite clearly from the West Village area
of NYC. Many days the sky is this brownish color, no stars.

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Roritharr
As someone living in Frankfurt, this site encourages another trip to Scotland
or Norway. I miss seeing stars.

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olfactory
Is there a way to make one of these maps show RF pollution at different
frequencies using similar models?

~~~
dylan604
This is a very interesting idea. In locations where serious radio astronomy is
conducted, there are restrictions on radio emissions in a large area around
the antenna. No wifi, no bluetooth, no cellphones, no anything.

An RF pollution map would be useful to see not only where a candidate spot to
build a new radio antenna might be, but would also be interesting to see the
areas around existing sites.

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arekkas
This is awesome! What data does this use? Does it correlate population density
with light pollution?

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dboreham
I don't think so. It probably uses imagery from some space based system.

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qplex
That's a lot of wasted energy.

Most people sleep at night anyway - no need to keep the lights on.

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pc2g4d
Poor western Europe!

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wheresvic1
Basically all of northern Canada

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deevolution
This is spectacular.

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etep
[https://xkcd.com/1138/](https://xkcd.com/1138/)

~~~
kibwen
Please see my other comment as to what this map is useful for. Furthermore, on
a global scale, light pollution is not equivalent to population; consider the
light levels of Indonesia, the world's fourth most populous country.

