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What are the limiting factors in this case

  1. Mar 20, 2008 #1
    What are the limiting factors in this case....


    I have quite recently shifted to this area in Thailand. This is a very small town, there are no big cities for more than 150km distance, & no special industrial towns nearby.

    Before coming here I had thought this will be a very good place for sky gazing even with naked eye, but surprisingly I have found it all opposite. The sky is extremely dark and I can't see anything except moon with an unaided eye.

    I Haven't been able to understand why... I think I don't know all the limiting factors which simply block easy watch of heavens.

    I'll be thankful for your replies.
  2. jcsd
  3. Mar 20, 2008 #2
    The toxic air pollution in some parts of Thailand contain pollutants that are 60 to 3000 times higher than health standards in developed nations. The sources are often open fires, including forest and open air cooking, so distance from major cities may not ameliorate visibility problems a lot. 150 km is not a lot when effluent is high in essentially in every direction around you. I don't know what part you are in. Prevailing winds are also an issue at that distance. Is a haze or darkish coloration visible on the horizon during the day?

    The other major factor is humidity. Even by itself high humidity can greatly reduce visibility. In combination with pollution particles it is far worse. Here in the states exceptionally clear nights are far more rare than when I was a kid, though better than a few years ago. It is really awesome to see a crystal clear view of the stars.
  4. Mar 20, 2008 #3


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    Staff: Mentor

    Well, depending on how recently you moved to the area, the moon itself may be the problem. It's near full now and for about the past week (and for the next week), it would blot out all but the brightest stars.
  5. Mar 21, 2008 #4
    Thanks for the information, you are right, I can see the haze during the daytime & there are simply dozens of open air cooking spots in every single area. Also no doubt about fires which are created by locals to either burn the garbage or useless forest woods...

    I am in Chanthaburi, 250km east of Bangkok, a small town famous for its gem trade. Toxic materials are also used such as beryllium for heating gems in bulk quantities.

    The best place where I was able to see crystal clear sky was in the south western province of Balochistan in Pakistan when traveling to Iran by road. There was no sign of any village for 100s of kilometers & no lights, haze or any sort of pollution, all & all a lonely huge dessert... The night view was soooooooooo amazing that words are not enough to describe it all it was just like a dream, I could see stars, a massive nebula which was streched all the way, I think that was the center of galaxy??.
    In short The Best scene I have ever seen

    I am really thankful for your reply, you have been a great help.
  6. Mar 21, 2008 #5


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    Staff: Mentor

    That would be the milky-way, our own galaxy - or at least one spiral arm of it. Whether the center of the galaxy was in view (it's a single point) depends on your location or time of year.
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