Quote:
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Originally Posted by swdw
Quote:
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Originally Posted by Nuc
I was cruising on the surface and saw the scene below. I check the Almanac from this download and sure enough on this date (Dec 18, 1941) moonset was to be 26 minutes after sunset. My question is; Is this an observable situation in the real world or would the sun's glare prevent seeing the moon?
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You mean like this?
http://www.igougo.com/travelcontent/...PhotoID=328270 |
Both the SH4 picture and the picture you posted are not possible.
The phase of the moon is a direct result of its angular distance from the Sun. The corollary to that is that each phase of the moon rises and sets at the same solar time, for instance, the half moon rises at exactly 9:00 pm and sets at 9:00 am solar time.
Therefore, in the SH4 screenshot, the moon is approximately a half moon. As such, it would rise 90º after the sun set, 3 hours at 15º per hour, exactly 21:00 as I said above. Instead of 90º SH4 renders it less than half a degree from the solar position, which would result in a new moon. We would be looking at the unlit half of the moon. You could not see it for the sun's glare.
Swdw, your shot is an obvious fake. The first giveaway is that the moon ½º from the sun would be at 1/720 phase, essentially a new moon as outlined in the above referring to the SH4 screenie. The other blatant error is that they chose to paste the moon in at half the size of the sun. In reality they are both about half a degree in diameter, so close to the same size that you'd need a micrometer on the image to tell the difference. At perigee the moon is slightly larger than the sun. At apogee it's slightly smaller. The sun also varies slightly in size depending on whether the Earth is at aphelion or perihelion. In either case the change in size is not discernable to the naked eye and they are essentially identical in angular size.
A nice concise confirmation of all I say can be found
here and a thousand other places.
OH! What about the setup in your Almanac above? The moon set 26 minutes after the sun. The earth rotates a degree every four minutes, so the moon would be 26/4 or 6½º above the sun or 13 solar diameters above. That's a very different spot from where SH4 renders it. Stand by for a plot, which I'll paste here.
You can see the moon labeled. It's a new moon, only 4/1000 illuminated, as I said 13½ solar diameters above the moon. This plot is two minutes before sunset, December 18, 1941. The green line on the bottom is the horizon. Astronomical charting courtesy of Cartes du Ciel, a masterpiece by Patrick Chevalley.
Time to go cut the grass!