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I'm writing a story. I want my ending to have the sun and moon visible in the sky at the same time. It is symbolism for the larger story.

Is this possible? I have tried searching and can't find anything that is making me feel 100% about the issue.

Obviously we've all seen the moon in the sky during the day but I was wondering if there were any times or places that would lend to seeing the Moon and the Sun *near each other but barring an eclipse.

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    $\begingroup$ Can you explain what you are asking. Everyone sees the moon and sun in the sky at the same time. It happens after sunrise for part of the month, and before sunset for part of the month. You say you know this, but then you imply it's only for an eclipse. $\endgroup$
    – Rory Alsop
    Commented Dec 6, 2023 at 22:37
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    $\begingroup$ They are generally visible at the same time at some point every day, except during a new moon. However, they only appear close together near a new moon, and the moon will just be a tiny sliver and not easy to pick out. I would recomend downloading some planetarium software like Stellarium to visualize it. $\endgroup$ Commented Dec 6, 2023 at 22:55
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    $\begingroup$ If there are eclipses, there obviously must be a time before and after where they are close to eachother. Thus you can get any angle between them, whatever you like. Every angle every month. $\endgroup$ Commented Dec 6, 2023 at 23:34
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    $\begingroup$ You answer your question yourself by saying “we’ve all seen the Moon in the sky during the day.” If it’s the day, then the Sun is visible! Ergo, the Moon and the Sun are visible together at that moment. As for being “visible close to each other” then no, that’s not really possible—although it all depends what you mean by “close.” $\endgroup$ Commented Dec 7, 2023 at 6:14
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    $\begingroup$ Welcome to Astronomy SE! I think you can leave this question post as-is (it might be closed, then it might be reopened) and also ask a new question. I see in your comment you mention "close to each other" which is probably a core element of your question that you forgot to emphasize. So why not ask the new question "Roughly how close can the Moon be to the Sun and still be routinely visible by eye during the day?" $\endgroup$
    – uhoh
    Commented Dec 8, 2023 at 10:09

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It is not only possible it is exceptionally common. When the moon is nearly new (and very close to the sun) it is not visible because the glare of the sun is too bright, and when the moon is nearly full, it rises at about the same time that the sun sets (and conversely it sets at about the same time that the sun rises) so the moon may be too low in the sky to be visible.

So it's not possible to see the sun and moon at the same time for a few days each month. But for about 75% of the month, the moon and sun can be seen together in the sky. One week after new moon, the half moon will be visible. This is called "first quarter". The first quarter moon will rise at about midday, and set at about midnight. So it is visible in the sky during the afternoon. A full moon happens one week after first quarter, and then one week after full moon the half moon is visible again. This is called "third quarter". The third quarter moon rises at midnight and sets at midday, so it is visible during the morning.

As I write, the moon is approaching third quarter. So go and look for it in the morning in the South-West sky. It won't be difficult to see. It won't be close to the sun. It is easier to see when it is far from the sun.

What is impossible is to have a full moon side-by-side with the sun. The moon is lit by the sun, so the only time it is full is when it is on the opposite side of the Earth from the sun. When the moon is close to the sun it will only appear as a tiny sliver, and will probably not be visible at all, due to glare.

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  • $\begingroup$ Nice answer. You may want to clarify that the Sun and Moon can be seen during the day for part of the day but not all hours of the day. Naturally it depends on the times of Moonrise/set and Sunrise/set. $\endgroup$
    – JohnHoltz
    Commented Dec 7, 2023 at 1:10
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    $\begingroup$ I think my examples make that clear "The moon rises at midday..." should clarify that the moon is only visible after midday $\endgroup$
    – James K
    Commented Dec 7, 2023 at 5:44
  • $\begingroup$ I disagree about the sliver-moon being not visible... I very often see an extremely thin crescent moon just as the sun is rising, and sometimes I can see the new moon just before dawn, made slightly lighter than space by reflected earthlight. Sure, it'll be impossible to see once the sun is well-and-truly up, but when it's low to the horizon the glare isn't enough to wash out the moon. $\endgroup$ Commented Dec 7, 2023 at 15:38
  • $\begingroup$ depends how much of a sliver. A good proportion of humankind are very interested in exactly when this sliver is first visible. But you'll never see a full moon next to the sun. That is the main point. $\endgroup$
    – James K
    Commented Dec 7, 2023 at 18:05
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When I was a child, I was outside during the day, I think in the backyard of our house, and I happened to look at the sky and see the Moon.

I was surprised to see the Moon in the sky during the day, since I thought of the Moon as being visible during the night. But there was the Moon in the daytime, right before my eyes. So I thought of that as learning something new, that sometimes the Moon was in the sky and visible during daytime.

Since the Moon orbits the Earth in an almost circular elliptical orbit, half of the time the Moon will appear in the hemisphere of the sky pointed away from the Sun, and half of the time the Moon will appear in the hemisphere of the sky that the Sun is in, and thus closer than 90 degrees of arc to the direction to the Sun.

This article has a diagram showing the Moon's orbit around the Earth and the direction that the Sun's light is coming from and how that affects the phases of the Moon.

https://www.pas.rochester.edu/~blackman/ast104/moonorbit.html

You will notice that whenever the moon is less than half full (a crescent Moon) it is in the same half of the sky as the Sun and less than 90 degrees from the direction to the Sun. And whenever the moon is more than half full (a gibbous Moon) it is in the half of the sky away from the Sun and between 90 and 180 degrees from the direction to the Sun.

I hope that diagram makes it clear that the Moon can often be seen the daytime while the Sun is up, for at least part of the daytime.

Of course, everyone knows that the visible sky seen from the surface of Earth is half, one hemisphere, of the total visible sky. Thus the zenith, directly overhead, must be 90 degrees above each and very point on the horizon, and every point on the horizon must be exactly 90 degrees below the zenith, and the visible sky must span 180 degrees from a point the horizon to the zenith to the opposite point on the horizon.

And it is obvious that when the moon appears full as seen from Earth, the Sun and the Moon must be on opposite sides of the sky as seen from Earth, and thus that the direction to the full Moon must always been 180 degrees from the direction to the Sun. When the Moon has other phases it can be much closer to the direction of the Sun. When the Moon appears new and invisible, the direction to the Moon is almost exactly the same as the direction to the Sun.

So if the full Moon must be 180 degrees from the direction the Sun, the Sun and the full Moon can not both be entirely above the horizon at the same time. If all of the Sun shows above the horizon and the moon is full, all of the Moon must be below the horizon t that place and it can only be seen from other places where the Sun is below the horizon. And if all of the full Moon is above the horizon, all of the Sun must be below the horizon at that location.

Thus the only way to see both the Sun and the full Moon at the same time is if they are both exactly at the horizon, with part of the Sun above the horizon and part below, and part of the full Moon above the horizon and part below the horizon.

And I hope that the logic in the previous four paragraphs is perfectly clear and it is perfectly clear to everyone who reads them that the full Moon and the Sun can never both be seen entirely above the horizon at the same time.

If you go to Google Maps and go to the corner of Gurney Street and Beach Avenue, Cape May, New Jersey, and click on the street view at 701 Beach Ave., which might be this url:

https://www.google.com/maps/@38.9305502,-74.9181682,3a,75y,180h,90t/data=!3m7!1e1!3m5!1sJTVZ1zqwi7aWmj-PsX4wBg!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3DJTVZ1zqwi7aWmj-PsX4wBg%26cb_client%3Dsearch.revgeo_and_fetch.gps%26w%3D96%26h%3D64%26yaw%3D277.47632%26pitch%3D0%26thumbfov%3D100!7i16384!8i8192?entry=ttu

And rotate the view, you can see that Cape May is very flat, like the ocean. If you look toward the beach and the ocean, you will see that the promenade widens there and extends out over the beach, with the convention hall in the center of that section and smaller building on each side.

One afternoon in the 1970s or 1980s, I was standing on the promenade there, to the right or western side of the buildings. I looked out at the ocean, and saw the full Moon low above the horizon, surrounded by blue sky.

And I thought that the Sun had to be entirely above the horizon for the sky to be be blue. And thus both the Sun and the full Moon had to be entirely above the horizon at the same time, which should be impossible.

So I turned around and saw a reddish setting Sun, entirely above the horizon.

And how can that be possible?

One) The visible part of the sky is not a hemisphere. If the Earth was flat, the visible part of the sky would be a hemisphere. But as you may have noticed, the Earth is not flat but a spheroid, and thus curves away below in the distance. Thus the horizon is more than 90 degrees below the zenith, and the visible part of the sky is more than a hemisphere.

Thus it would be possible for the Sun and the Moon to both be more than 90 degrees below the Zenith and also both above the horizon.

Two) The atmosphere can refract or bend light, especially if those objects are near the horizon. Refraction can make objects near the horizon appear a few degrees higher and closer to the zenith than they are. So even objects below the horizon and sometimes appear appear above the horizon.

Three) It is hard to tell with the unaided eye whether the Moon is exactly full. Thus the Moon can appear full to the naked eye a day or two before and after the actual full Moon. And thus the Moon can appear full - as well as the naked eye can tell - when it is a bit less than 180 degrees from the the direction to the Sun.

So the first two factors, and probably the third, combined to enable me, and other people in other places and times, to see both the Sun and the (apparently) full Moon totally above the horizon at the same time.

And if someone is a very careful writer, they may want to check to make certain that the phases of the Moon and the angle between the Sun and the Moon, and the time of rising and setting of those bodies at his location, will be correct for the past or future date they have selected. Or if they wish to describe a specific relation between the Sun and Moon, they will want to check to make certain they have an accurate past or future date for that relationship to be seen.

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  • $\begingroup$ Refraction usually is around 0.7° near the horizon, so not"'several degrees" (but enough to show sun and moon 180° apart concurrently on a 180° view) $\endgroup$ Commented Dec 7, 2023 at 6:45
  • $\begingroup$ The Moon's orbit is inclined by a little over 5° to the ecliptic, so it's possible for it to be ~5° (roughly 10 Moon diameters) above the anti-solar point at Full Moon. $\endgroup$
    – PM 2Ring
    Commented Dec 7, 2023 at 10:38
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The moon is outshone and backlit the closer it comes to the sun. Given that your field of focused and detailed vision is <50 degrees, by the time both objects are close and in focus the apparent magnitude of one is so much brighter than the other that you're retina cannot process the light of both simultaneously.

If you can use a shaded disc on top of the sun, like a piece of 90% car blindd, there is a far higher chance of both being in your field of view simultaneously.

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