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Sometimes I observed there is moon on sky at noon and sun is also shining.

How is this possible?

I also observed dull moon is still on sky at 7:00 AM to 8:00 AM while sun is rising. My local time is UTC+5.

If possible, please explain it in simple words without using advanced astronomy terminology if possible, thanks!

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    $\begingroup$ @SteveLinton I disagree! The OP has specifically asked please explain it in simple words without using advanced astronomy terminology An answer that starts with The visual geometric albedo of the full moon is 12.5%, but much less at other phases. and continues with and since the intensity of light falls off as $\propto \frac{1}{r^{2}}$ ([inverse-square law) doesn't really fulfill that, so it's not a good duplicate because it doesn't really answer the OP's question as asked. $\endgroup$
    – uhoh
    May 9, 2019 at 13:15
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    $\begingroup$ Are you wondering why the Moon is sometimes above the horizon at the same time as the Sub, or why it's bright enough to see? $\endgroup$
    – Steve Linton
    May 9, 2019 at 13:18
  • $\begingroup$ @SteveLinton More about the technical definition of geometric albedo in this answer. Have a look at my answer, if you feel that it better answers the OP's question than your linked duplicate, you can consider withdrawing the close vote. There are several users here that might be configured to auto-close anything that has one plausible close vote. In this case I don't think it helps. update: too late, the insta-close has begun. $\endgroup$
    – uhoh
    May 9, 2019 at 13:19
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    $\begingroup$ @SteveLinton if you are trying to clarify the meaning of the question, how can you simultaneously vote to close as duplicate? That's putting the cart before the horse. $\endgroup$
    – uhoh
    May 9, 2019 at 13:29
  • $\begingroup$ This is like asking why you can see your book while you have a lamp on over your desk. Think about it for a bit... $\endgroup$
    – Carl Witthoft
    May 9, 2019 at 17:36

3 Answers 3

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Let's look at what the difference is between day and night.

In the day time, the air that's between you and the Moon is in the sunlight, but at night, that air is in the dark.

Day or night though, the air is still transparent (you can see the Moon through it), and the light from the moon is mostly unaffected.

When it's in sunlight, the air scatters some of the sunlight in your direction. For the parts of the Moon that are bright, they are so bright that they look white.

But the dark parts of the moon don't look black to you on Earth because there's still the fainter blue-sky light scattered by the air.

Moon during the day with bright blue sky light

Moon during the day

Source

Moon at sunset with faint blue sky light mixed with Earthshine

Crescent Moon with blue sky

Source

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If you turn your back to the sun and look at a building, the sun shines on the building and you can see it. If the building is very far away but very big, you can still see it because the sun is still shining on it during the day. If you think of the moon as a very large object very far away in the same direction as that building, you can see that the sun lights it up. The only time the sun doesn't light it up is when the moon is on the side of the earth towards the sun. Otherwise, the sun will always light up the moon. You can see it because it's bright enough that the sun doesn't wash it out like it does the stars.

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Let's look at our solar system from above:

enter image description here

The night side of Earth is the hemisphere facing away from the Sun. The Moon orbits around the Earth, on a path that takes 28 days. So for half of that orbit (14 days, from Last Quarter to New Moon to First Quarter), the Moon is visible from the day side of the Earth.

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  • $\begingroup$ Although your graphic shows the moon in the night sky... :-) $\endgroup$
    – Alexis Wilke
    May 9, 2019 at 17:24
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    $\begingroup$ not any more ;) $\endgroup$
    – Hobbes
    May 9, 2019 at 17:33
  • $\begingroup$ @Hobbes I've proposed that the question be reopened on the basis that the question asks for a simple, non-technical explanation and that can't be found at the other question. I see you've also taken the time to write a simple explanation, perhaps you could consider a re-open vote as well? $\endgroup$
    – uhoh
    May 9, 2019 at 23:58
  • $\begingroup$ IMO it's pretty well covered by the accepted answer in the linked question. Mine just duplicates that. $\endgroup$
    – Hobbes
    May 10, 2019 at 8:21

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