How does the position of Moonrise and Moonset change?
I have been enjoying the moon rise for 4 or 5 evenings recently. Our house is situated with mountains to the east so it is very easy to “mark” the spot on the horizon where the moon comes up each evening. QUESTION: Why is there such a great variation in the place on the horizontal plane where the moon rises from one evening to the next? There has been as much as 25 degrees or more difference in the spot that the moon clears the horizon from one evening to the next. The position of Moonrise and Moonset, like that of Sunrise and Sunset varies as the Earth goes around the Sun, but also with the phases of the Moon. Let’s start with the position of Sunrise/Sunset, which varies as the Earth orbits the Sun. Because the Earth is inclined at an angle of 23.5 degrees to the plane of its orbit, and because the direction of the inclination (with respect to the stars) does not change as the Earth moves around the Sun, sometimes the Earth is tilted towards the Sun and sometimes it is tilted away fro
