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Stargazing Strange evening sky

  1. Oct 29, 2017 #1
    It's early evening here (Ireland).
    The Sun is definitely set, and there is a bright half Moon.
    However there are no stars or planets visible at all, anywhere in the sky.
    There is no cloud, at least nothing substantial, the Moon is perfectly bright, no sign of cloud in that part.
    There are low level street and house lights, but I don't think that's what it is.
    Stars and planets are usually well bright enough to see on a generally clear night.

    Any clues?
  2. jcsd
  3. Oct 29, 2017 #2


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    After sunset there is a period of twilight, where the sky is light enough so that starts are not visible.
  4. Oct 29, 2017 #3


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    Damn, rootone, I'm afraid you're going blind :smile:
  5. Oct 29, 2017 #4


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    A faint layer of high level cloud will not affect the appearance of the Moon to the unaided eye but it can render anything else not visible against the twilight sky.
    If you stand and watch for ten to fifteen minutes you often see just one bright star first and then the other bright ones become visible, one by one. The sunlight is getting less and your dark adaptation is getting better. I believe that your eyes need to get used to focusing properly at that time, too.
    A few evenings ago, the sky was about 5/8 covered with thick, dark, lowering clouds and they all had deep red undersides - even those to the East. The colour was crimson and not like the typical orange of a setting Sun. There was a lot of dust from the Sahara in the air a few days previously and that effect on the sky actually made the (London) TV news. But I guess that whould have all cleared before our crimson clouds so I have no idea what caused them.
    I live to the East of London and we are very fortunate with our sunsets, probably due to all the pollution over the capital. It's an ill wind that blows nobody any good. Take Turner's and Monet's stunning London sunsets; all due to smoking chimneys (plus a bit of imagination, I guess).
  6. Oct 29, 2017 #5
    Thanks, the stars are back now.
  7. Oct 30, 2017 #6


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    1. The moon is so bright it is drowning out the other stars and preventing your eyes from adjusting enough to see them. (like staring into a car's headlights) This is certainly part of it.
    2. If it is humid, the sky's transparency could be low, causing the stars to be blocked. You wouldn't necessarily notice the difference with the moon. This is noticeable during the day as the difference between a deep blue and a light blue sky and will differ by altitude angle (how high up you are looking).
    Last edited: Oct 30, 2017
  8. Oct 30, 2017 #7


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    Read 'Nightfall' by Isaac Asimov if any of you are worried about the stars disappearing for a long time and then suddenly appearing again .
  9. Oct 30, 2017 #8
    There are also no bright planets on view at the moment, except Saturn which sets quite early.
  10. Oct 30, 2017 #9
    Yes, I was a big Asimov fan, still am really, but I think I probably have read all the best stuff, and that is one of them.
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