posted by Jamie on .
On the Vernal Equinox, you see the Moon in the Waxing Gibbous Phase at an angle of 45 degrees above the eastern horizon. What is the approximate local time?
On the Autumnal Equinox, you see the Moon in the Waning Crescent Phase at an angle of 45 degrees above the western horizon. What is the approximate local time?
In the first case, the moon (at that phase) is still about three days from being full, and rises about 3 hours before sunset. It would be 45 degrees above the horizon at sunset becasue it rises 15 degrees per hour. Therefore it is sunset, which occur at about 7 PM (Daylight Time) on that equinox date.
In the second case, the sun rises 7 AM daylight time. Almost all of the USA is on Daylight time at autumnal equinox). In waning crescent phase, it sets about 3 hours before sunrise. Because of its 45 degree above west location, it will set in about three hours. So the time is about local sunrise or 7 AM, Daylight Time.
These answers are approximate. Precise times depend upon longitude within the time zone and other factors.