Here in south London I have just seen that the sun will set at 16:45 hrs but the moonrise does not happen until 2hrs later 18:45 hrs what is happening in this two hour void, will it be too dark to see?

  • $\begingroup$ When you say "will it be too dark to see?" do you mean will the moon be too dark to see, or are you asking about how dark it will be outside? $\endgroup$
    – Dr Chuck
    Commented Jan 30, 2021 at 20:07
  • 7
    $\begingroup$ I know we're in lockdown and everything, but you could try looking out your window at 17:30 to see what it is like. Testing out a theory by making observations is the basis of the scientific method. $\endgroup$
    – James K
    Commented Jan 30, 2021 at 22:30
  • $\begingroup$ a bit presumptuous that everyone lives in a nice place with a window $\endgroup$
    – uhoh
    Commented Feb 1, 2021 at 4:33
  • $\begingroup$ It will be similar to a evening/night with no moon. It is not that clear what you are asking for... $\endgroup$
    – Alchimista
    Commented Feb 1, 2021 at 9:34

2 Answers 2


The Moon rises approximately 50 minutes later every night. Simplistically, the new moon will rise and set roughly with the Sun, while the full moon will be opposite the Sun (as in, it will rise when the Sun sets, and set when the Sun rises). Look at the Moon the next night and it should be rising about 19:35 from the day mentioned in your question.

This +50 minute time is due to the Moon's orbit around Earth, which takes roughly 29 days.


Whether it is light enough to see will depend on the local streetlights and the lights coming from buildings, etc If you are in a city named South London there will be plenty of light.

The period shortly after sunset is called twilight because light from the sun below the horizon is still being reflected downwards, so it will take time for the sky to turn black.

And it is possible that someone could see well enough to walk around by starlight. Decades ago I used to walk up a hill to watch the stars through binoculars. So obviously there was enough light for me to see where I was going, light from the stars and maybe from nearby light sources in the neighborhood.

Anyway, if this place, South London, is a populated community, there should be enough light from various local sources to see where you are going. And possibly the interval between sunset and moonrise might be the best time to look at the stars, if light pollution from the neighborhood doesn't make them invisible.

When I go to bed at night my bedroom is almost totally dark. But if I wake up in the night I can see much better in my bedroom, because my eyes have become dark-adapted while I slept. So if you are in the dark your eyes should gradually adapt to seeing in the dark and you should start to see things better.


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