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Space Science

Atlas of Worldwide Light Pollution 234

Posted by michael from the deepness-of-the-sky dept.
mgarraha writes: "Researchers at the University of Padua and NOAA have analyzed DMSP data to produce a new atlas of night sky brightness due to artificial lighting. Previous maps only showed the distribution of light sources. Their paper will appear in the Monthly Notices of the Royal Astronomical Society. Here is an AP article."
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Atlas of Worldwide Light Pollution More

Atlas of Worldwide Light Pollution

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  • I notice that there are chunks of the middle east and northern Africa that have been erased. Political lines are even gone. Is this a mistake, or are we protecting some valuable light pollution data, here?

    Odd.
    • Canada has been excluded from the world, and you're worried about the Middle East and parts of Africa?
      • Actually, it looks like Toronto has some of the most extensive lighting in eastern North America. Boston, NY and D.C. are much more constrained to a small area, where Toronto spans a very visible area with its brightest illumination.

        Further north, most of Canada is like Maine. Even the well settled areas tend to have little light pollution compared with major cities.
  • Anyone know the address to a smiliar satallite mosaic of the worlds EF emissions? I saw it online once and have been looking for it ever since.

    Beautiful image ( although scary ) outlining the coasts and air/sea shipping lanes.
  • Here are some useful tools for estimating the light pollution in your area.

    Website using CGI script to estimate light pollution:
    http://www.darksky.org/ida/darksky/ [darksky.org]

    Java Applet to estimate light pollution:
    http://www.darksky.org/ida/darksky/darksky.html [darksky.org]

    To help you use the above tools, you'll need to know your latitude and longitude in degrees. Just type in your zip code at the bottom of this page:
    http://tiger.census.gov/cgi-bin/mapbrowse-tbl/ [census.gov]

    When converting latitude and longitude for use in these tools, use a negative number to denote South and West (W); use a positive number to denote North (N) and East (E). For example, "49.147247 N" = "49.147247" and "73.996206 W" = "-73.996206".

  • compare light to population (Score:4, Informative)

    by jonbrewer ( 11894 ) on Saturday August 11, 2001 @08:52AM (#2122579) Homepage

    Compare light to population and no one should wonder why the US is the biggest polluter in the world. Put together the light intensity of China, India, and Indonesia, and you've got half the population of the world, yet they still put off less light than the NorthEast corridor of the US. That's 3,000,000,000 people to 60,000,000.
    • 60,000,000??? Not sure where you are getting this, but last time I checked (and the census people) we are actually at 281,421,906. Point still taken, but there are a bit more than 60 million over here.
    • Why did you pick the US as an example? From those maps, it looks like Europe's lights are far brigher and denser...
    • Well, we have no choice then but try to become like Inda, China or Indonesia.
      You start first by giving up your computer and your car.
    • Oh ya, now light is "pollution." Maybe we'll have conferences on how astronomers in third world counties should be compensated (funny how it all comes down to writing a check) for this light pollution. Or how we should all retrofit out stree lights (again, qui bono?).

      Light means prosperity. And prosperity generally means taking better care of the environment. When China is lit up like the U.S., you can bet it will be easier to breath there, too.

      • Light means prosperity. And prosperity generally means taking better care of the environment. When China is lit up like the U.S., you can bet it will be easier to breath there, too.

        *black stare*

        Pardon me while I laugh hysterically at that comment. Yes, American air is so much cleaner than the air in the nonindustralized world. (Including parts of Commiela--er, China.) Of course, I suppose it's obvious -- what with all the smog warnings they face in the third world. It is truly terrible that parts of their population can't leave the house due to air polution generated by all those consumer automobiles and industrial infrastructure they don't have. Riiiiight...

        BRx ;)

        • You're kidding, right? Los Angeles on its worst day has better air quality than most cities in (eastern) Europe and China.
          Reason: Coal. They burn it, we don't
        • What, you mean you actually were surprised that an american was ill-informed about how the world works, and that the US isn't heaven on earth in all aspects?

          I wasn't. I've given up on them. I fully expert the US to start the next world war, trying to impose The American Way onto everyone.

          (Yes, I'm sacrifying two whole karma-points on this. I hope it will open someone's eyes though .. )

          • Oh spare us. The air in the US is a heck of a lot nicer than in the typical European city. Here's a clue - We don't still put lead in our gas like they do in Europe. The sulphur content of our fuels is far far less too.

            So yea, the air in the US, even in most large cities, is far cleaner than the air in say Europe. You want to talk about polluters, then get the Europeans to clean up, they produce far more pollution per kilojoule used than the United States.

        • Ahem. *blank* stare.

          :p

          BRx.

      • Guess I wasn't clear in my comment. I was talking about pollution in general... most of that electricity is produced by coal, and it is wasted so carelessly. I don't think of light as being pollution until I'm far away from it, and that's not often.

      • Doh! (Score:2)

        by Zigurd ( 3528 )
        Doh! That should be "cui bono?"
  • I feel kind of ignorant, but what's that huge bright spot off the coast of Argentina? It looks too big to be the Falkland islands.
  • Being a Brit as I am, it's interesting to me that Northern Ireland is the only piece of that country showing lots of light (apart from Dublin)... unless I am to make some tasteless joke about bombs, I can only assume this is a result of intensive British building, as opposed to the wonderful (and wisely) undeveloped countryside of Ireland.

    *Sigh*

  • DMSP earthlights image (Score:4, Informative)

    by jmorzins ( 86648 ) on Saturday August 11, 2001 @08:01AM (#2125757)
    Some of these satellite photos are really fun. One of my favorites [nasa.gov] also uses data from the Defense Meteorological Satellites Program (DMSP). They spent months taking pictures of the night time earth, and assembled a beautiful composite image of all light-emitting sources on the earth's surface.

    It's a map of light sources, and shows some really interesting structures. The Nile is much brighter than the rest of Egypt, the central U.S. is a grid of cities, and there's a railroad stretching across Russia to the Pacific Ocean.

    A small version of the image was an astronomy picture of the day last November (http://antwrp.gsfc.nasa.gov/apod/ap001127.html [nasa.gov]), and a larger version of the image is also available (http://antwrp.gsfc.nasa.gov/apod/image/0011/earth lights_dmsp_big.jpg [nasa.gov]). There's a short writeup at http://earthobservatory.nasa.gov/Study/Lights/ [nasa.gov].

  • Better lighting (Score:5, Insightful)

    by Midnight Thunder ( 17205 ) on Saturday August 11, 2001 @08:06AM (#2125763) Homepage Journal
    If we are seeing so much artificial lighting from space, then it says something about the lighting used. If the light sources were only pointing their light towards the grounds, using shrouds to avoid upward distribution of light, then we should see a darker night view. Also, any light source that can be seen from space is probably also using more energy than necessary. Being environmental friendly is not always a question of finding an alternative, but simply using what we already have in a smarter way.

    • Re:Better lighting (Score:2, Informative)

      by RobYoung ( 451535 )
      Most of the light shown in the picture is probably being reflected off of the ground, so lights that just point down will not help. Unless we put a giant shield over the entire earth, then no light would get out and we could see the night sky.... nevermind. :)

      One thing to point out, is that the map is using mercator's projection (a way of making a sphere look like a square on a map) and it makes things near the equator a lot smaller than the land far from the equator. This makes places like india, australia and the malasia area a lot smaller compared to europe, canada, and northern US. Those cities in australia, for instance, are a lot larger than some of the canadian cities shown, yet it looks like they give off a heck of a lot less light. I don't think it is the amazing lighting technology they are using.

      • What Australian cities are larger than what Canadian cities? I think the only Australian city the size of Toronto or Montreal would be Sydney.

        I think it may actually be the case that Australia has less light pollution. One more reason to make me want to move there. :-)
    • Ummm...you know why you can see the sidewalk when a streetlight shines on it? That's right, the sidewalk reflects light. Now, if you just decide that we can go ahead and pave the Earth with non-reflective concrete, your idea will have some merit. Until then, unfortunately, we're hosed.

  • Waste (Score:5, Insightful)

    by jridley ( 9305 ) on Saturday August 11, 2001 @08:13AM (#2125768)
    Disclaimer; I'm an amateur astronomer and a member of the Int'l Dark Sky Association. The thing that drives the light pollution activists most nuts is that this is nearly all waste. The majority of lights, and nearly all of the lights that you see in situations like this, are badly designed lighting fixtures that spill much (sometimes more than half) of their light uselessly into the sky. People put in lights to illuminate buildings and roadways, then they use crappy fixtures that send more light into your eyes than onto the intended target. Bad lighting is sometimes worse than no lighting at all. I've certainly driven down roads where I could see better after I get out of the lighted street area, because of the glare from the lights directly in my eyes. I've also seen really bad flood lamp security lighting where a robber could walk right up to the house and not be seen, because again, the lamps are glaring in your eyes so bad you can't see in the shadows. It's this kind of thing that gets me going. That, and people that are so scared of the boogeyman that they have to have several thousand watts of lights on their property up all night long.

    • I'm a pilot. Upshining light... IS GOOD. (Score:1, Informative)

      by Anonymous Coward
      I'm a pilot. I fly small planes, not big commercial ones. I don't have all the fancy radar, guidance systems, imaging, computers, etc. do do most of the flying for me like the big commercial jets.

      Well, if you thought driving at night on an unlit highway with no headlights is bad, then you know what flying at night is like all the time.

      I for one delight in being able to use the artificial upshining night lighting to navigate by. It makes the skies SAFER. And that's more important than some stargazing.

      If you want darkness, go drive to the boonies.


      • Shrug, fly on decent moonlit nights or just don't fly at night. If it's that dangerous, don't do it.

        I would rather have much less light pollution and far darker nights, even if it inconveniences a few pilots.

        ~Cederic
        ps: The skies would be a damn sight safer if people didn't fly in them.

    • That, and people that are so scared of the boogeyman that they have to have several thousand watts of lights on their property up all night long.

      The worst, it seems to me, are large car dealerships. For some reason they seem to have amazingly bright white lights glaring on their lot all night. Why? Is it theft prevention? Or is it to make the lot look like daylight so that people driving by will see beautiful cars? In any event, it sickens me. Last winter, I was driving down from Berkeley, CA to somewhere near Monterey. We passed one of those mega-mall car dealerships which was a ways away from downtown anywhere. And it was the brightest damn thing around. Later, from where I was staying near a peak in Monterey, I could see the general glow of light pollution around the area-- with this huge ugly bright spot standing out at that car mega-mall. A blight on the landscape. It was truly depressing. I really wish I had had a tactical nuke at that point. That would have briefly been brighter, but thereafter would have made sure that nobody built anything else on the site for a while.

      -Rob

      • The worst, it seems to me, are large car dealerships.

        IDA [darksky.org] also likes to talk about gas stations. Some are more brightly lit at night than most offices are during the day! It's as if each gas station feels a need to light itself more brightly than its neighbors, assuming a correlation between foot-candles and sales revenue. I think I will start boycotting the worst offenders just to be contrary.

    • Disclaimer; I'm an amateur astronomer and a member of the Int'l Dark Sky Association.

      I live (when I am not at uni) in Coonabarabran, near the largest scope in Australia. Looking at the map of .au - it seems that Coonabarabarabran is the little spec of light just north of the larger spec of light that I suspect is Dubbo. It must be, because we are the only town around the place. But the only thing we have is a football stadium (that wastes an incredible amount of light).

      I remember the 10 hour exposure that David Malin took a few years back, pointed in the direction of Sydney. Sydney is 500 kms away, yet you could see Sydney, a small city to the north, and a small city to the south. Now - Coona probably contributes just as much light to the scope, despite having a few laws in place to curb excess lighting.

      It is actually quite scary - I can't see a thing in Sydney - last night I couldn't tell whether clouds or the lighting was stopping me seeing the sky. But Sydney is a tiny emitter compared to some .us states.

    • The GOOD news in New York State is that both the State Assembly and State Senate have passed anti light pollution bill. It's waiting for the Govs signature. It requires full cutoff lights on Govt projects, and outlaws light trespass

  • Can anyone explain the very bright zone off of the southern tip of South America?
    • The Falkland Islands / Malvinas catching fire?
    • Atlantis alive and kicking
    • A bug sitting on the satellite sensor
    • ...?
    Just wondering...
  • For the love of god, will somebody volunteer to re-raster the seal of the Istituto di Scienza e Tecnologia dell'Inquinamento Luminoso for them? It's a mission of mercy, folks.

  • Just take the Triana [slashdot.org] and put it on the opposite of its intended position, so it only sees the dark part of the planet. Instant Light Pollution data, and a space project saved as well :-)

  • Acording to this I left my porch light on again
  • This [nasa.gov] is a picture along the same lines, only IMHO more awe-inspiring.

  • canada? (Score:2, Funny)

    by slave ( 52995 )
    Northern Canada is so dark that the researchers forgot it existed.

    • Re:canada? (Score:1, Interesting)

      by RobYoung ( 451535 )
      Ya, it kind of annoyed me that the northern areas of canada were cut off. They just barely got edmonton on there. It would have been neat to see some of the northern towns in the yukon and the territories (and for you americans, Alaska). There is one "earth at night" image that a different poster (jmorzins) linked to, Here [nasa.gov], that shows all the way up to the north pole. It is interesting since every little town and research site up there seems to have at least one light turned on.
  • The Falklands have been mentioned, of course.
    But the really odd thing is the *huge* patch of fuzzy light just north of the Outer Hebrides, North-West corner of Britain.
    It's roughly where I'd expect the Faeroe Isles to be. The Faeroes are a small cluster of a dozen or so very small islands.
    And before any irate Faeroese start to hassle me, I'm from a very small island off the NW of Britain myself!

  • Wierd places (Score:2, Interesting)

    by jamieo ( 22197 )
    The maps's a bit wierd. What's all that down near the Falkland islands? It's almost all sea down there?

    Also, look near south west Kashmir, it reckons the area is as light as much of Europe.

    Nigeria looks pretty light near the coast too - spending all that oil money eh?

    It's interesting to pick out places - Cairo and the Nile valley in Egypt. Around Bangkok and further south to Kuala Lump and Singapore. Also the sultan in Brunei is leaving his lights on a bit too much ;)

    Tibet must be the darkest place on earth I reckon. Then again, maybe Somalia.

    Jamie
    • Try looking at New Zealand, according to that map, Timaru, a town of population 10-20 thousand is brighter than our largest city of 1.5 million. It's almost as bright as Sydeny, population 3.5 million, the same as teh whole of NZ!

      I know my parents often forget to turn the outside lights off, but they're not _that_ bright :-)
    • What's all that down near the Falkland islands?
      That's not the only problem. Look at the Korea Strait, between Japan and South Korea. As far as I know there are no oil rigs there to make that sort of light.

      Also note that the London-like lights near Nigeria are actually in the Gulf of Guinea.

      There are lights in the North Sea, though I can write those off to drilling.

      Anyway, quite an interesting idea. Some cities are easy to pick out, as is (for example) the Lower Nile and the associated delta.

      In response to another poster, the entire world is not included in this atlas. If you look closely at the big world thumbnail [lightpollution.it], you can discern the areas of the world that they've actually surveyed. Apparently they gave low priority to oceans, Siberia, and Canada.
      • Blockquoth the poster:
        Look at the Korea Strait, between Japan and South Korea.
        The allegation has been made, in the past, that this could be the Japanese squid-fishing fleet (really), who use bright lights to attract the squid.
    • Yes, I noticed that. I find it very hard to believe that the Falkland islands are one of the brightest spots in the southern hemisphere - does oil drilling really produce so much light? I used to live in Denver, and so I find it hard to believe (after seeing the excess there, and the lack of stars) that the much smaller cities of Calgary and Edmonton further north are so much brighter. As for the darkest place on earth... try the south pole in winter.
      • As for the darkest place on earth... try the south pole in winter.

        No, the sun's never far below the horizon. you get more of a perpetual twilight.

  • OK, OK, OK! (Score:5, Funny)

    by Mononoke ( 88668 ) on Saturday August 11, 2001 @09:01AM (#2145695) Homepage Journal
    I'll take my damn christmas lights down!

    You didn't have to go to so much trouble just to nag me.

  • The page seems to imply that light pollution always impacts the visibility of the night sky the same way, and that's not quite true. In a given area, Chicago for example, the more lights are on, the more diffuse light you'll see when you look up into the sky and the fewer stars you'll notice. However, if you use the same two light levels in Arizona, at the Grand Canyon for example, you'll be able to see more stars than the equivalent cases in Chicago.

    This is due to other atmospheric hazes -- in Chicago there's all sorts of moisture in the air and other aerosols that reflect the light pollution back to you when you're looking up, thus making it harder for you to see stars. But under clean air there can be a huge amount of light pollution around you and it won't affect the sky brightness very much at all.

    I've seen the Milky Way from the city of Tucson, one of those very bright spots, but never from my home of St. Louis despite the fact that they're both hopelessly light polluted, and this is why.

  • Atlas of Worldwide Pollution (Score:4, Interesting)

    by Pretor ( 2506 ) on Saturday August 11, 2001 @08:40AM (#2146567)
    I think an atlas of the worldwide pollution would be much more interesting. Especially in a time when the Kyoto Treaty is dangling. Pretor

  • The Milky Way Is A Spectacular Sight... (Score:5, Insightful)

    by cybrpnk ( 94636 ) on Saturday August 11, 2001 @07:30AM (#2147599)
    I live in the murky Eastern United States and if I can see a half a dozen stars from my backyard it's a good night. A few years ago I spent six weeks at White Sands Missile Range in New Mexico and one night several members of my team drove out to a remote corner of the site to take a picture of one of those comets that was big news in 1996 - I forget it's name. I thought the comet would be the high point of the night. It wasn't. Folks, when you are laying on your back looking up at the whole Milky Way splayed out above you, and you can really SEE that thing streching across the sky, it is a truly life humbling experience you will always remember. You almost think you could fall off the planet into the void. There is one hell of a lot more to see out there than a screen resolution of 800x600 pixels will ever show and it is worth the effort to get to dark skies to see it.
    • There is one hell of a lot more to see out there than a screen resolution of 800x600 pixels will ever show...

      Yeah, but full-FOV retinal scanning displays will be able to recreate that same experience (minus the the pile of dogshit you just stepped in).

      • Actually, it was an anthill. And you know, what you've said is funny and absolutely mindnumbingly frightening at the same time. Science - and "life experience" - isn't about coming up with better ways of experiencing what we ***think*** is out there - that's the definition of entertainment. Science and "life experience" is doing our best to observe what ***really is*** out there. And as science becomes more and more depenent on machines to aid our powers of observation we must work harder to consciously be aware of this separation between science and entertainment. Hey, when they get those laser retinal displays [washington.edu] perfected I'm gonna try em out, too. Should be amazing. The video games will be VERY entertaining and that's a good thing. But if it's showing me a picture of the Milky Way that came off a hard drive somewhere as a tiff or jpg file, that's going to be a lot closer to entertainment than a life changing experience flat on your back in the New Mexico desert. We need both to be all we can be.

    • Re:The Milky Way Is A Spectacular Sight... (Score:5, Interesting)

      by Ronin Developer ( 67677 ) on Saturday August 11, 2001 @09:20AM (#2118285)
      I couldn't agree with you more. When I was a young teen, I lived in the suburbs of Philadelphia. Because I had such and interest in astronomy, they allowed me purchase my first telescope, a 4 1/4 inch reflector from Edmund Scientific. I could go out into my back yard on almost any given night and have a clear sky (weather permitting, of course) and see most of the stellar sights. It was amazing and awe inspiring. We'd go to farmlands of Lancaster and it was just like you could fall off the Earth.

      Today, I live even further in the "country" and can see almost nothing. Yes, there are a few nights when I can see the stars, those are the nights of power failures. It's very sad. As real-estate developers continue to build larger, more luxurious homes with overzealous lighting in already heavily populated areas or buy out the precious open space, the situation just keeps getting worse.

      In the 60's and 70's, the sky was still pretty amazing. No wonder we wanted to go into space. Now, we look up and it's not quite so awe inspiring...sorta like a polluted beach or something. "Who wants to go there???" we ask.

      People wonder what the big fuss is all about. But, as the previous poster stated, it truly is a humbling experience to look up and see the heavens as our forefathers did hundreds, if not thousands, of years ago.

      In some respects, the Californian's are lucky. With the rolling blackouts, maybe they'll get a glimpse to see what we are all missing.

      • Yes. My experience:

        I grew up on a farm in an area that, on the current referenced map, is light green. In the 1950's the area, like so many others, would have been black (had the technology for such an image existed).

        It was corn harvest time in the midwest, a cold November night. I, a boy of about eight years, was holding the flashlight to help my father back up a wagon-load of corn to the elevator (to the urban dwellers, the term 'elevator' also refers to a sort of conveyor belt thing that lifts the grain to the top of the storage bin).

        But boys will be boys (or, children, as it were -- no need to discriminate here), and the onyx sky overhead, embedded with diamonds, beckoned.

        I knew at the time that the stars were far away, far farther that I could, at that time or any time within my reach, hope to travel. But I knew I could go there in spirit. And I knew a way...

        I raised the flashlight and aimed it at a promising star; I then moved the beam outward in a spiral path to cover as much of the cosmos as possible. This gesture, I knew, would not redound to me in any way during this life.

        But I knew then, and still know, that this beam -- four decades now on its illimitable tour -- still travels as _my_ message to other worlds.

        And this, apart from astronomical considerations, is the magic that light polution destroys.
    • I went sailing round Britain a couple of years ago, even a few miles off shore (about 10), was just amazing.

      Here in the UK there is almost nowhere devoid of light (desert light), as you are never really more then 20 miles from a town. Most of the land (especially here in the north west) is disgustingly light, you're lucky to see venus and mars, let alone anthing bigger. I go to Exeter Uni and I was amazed the first night i was there walking back from the pub - even a mile out of town, on a large campus, you could see so much more then near Manchester.

      But nothing will beat the boat.

      Regarding the map - what is the lights in the North Sea? Oil Rigs?

    • Re:The Milky Way Is A Spectacular Sight... (Score:1, Insightful)

      by Anonymous Coward
      Yup, I can confirm this. I've lived in heavily populated areas for my entire life, and with my typical computer-user nearsightedness didn't think much of the stars.

      Then I took a trip down US 84 through northern Texas. Let me tell you, when you can see stars out the *SIDE WINDOW OF THE CAR*, you really are in the middle of nowhere.

      We parked in a rest area outside Post, TX, and you could see them all the way down to the horizon.

      If you don't think constellations are impressive, then you just haven't gotten to a place that's dark enough.
    • The comet was Hale-Bopp. I live in Los Alamos, elev. 7200 feet. If you are willing to drive for about 20 minutes, you can be 800 feet higher, in the middle of the Jemez Mountains, and quite separated from manmade lights. The night sky -- the real night sky, not the four stars and an airplane that the city-dwellers get -- is staggering. The astronomers are fighting a losing (lost?) battle, but I am glad I have seen just where we fit.
    • A couple of points:

      (a) seeing the universe laid out for real is awe-inspiring and more than a little humbling. I think that if more people were to see the real night sky more often, there'd be a significant attitude change. When you realize just how insignificant and impermanent we humans are, the bullshit in life isn't so important any more.

      (b) street lights actually increase crime rates. No one wants to wander the streets in the dark, it's a bugger to break into a house when you can't see what you're doing, and it's difficult to be unseen when your flashlight turns out to be the brightest thing in the neighbourhood.

      (c) if you really want to be impressed, take up backpacking and head into the mountains. There are some remote areas that make the normal "real" view from out-of-town look about as cheesy as the out-of-town view makes the in-town view look!

      (d) in particular, aim to be in the mountains during a meteor shower. Ye godz!

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