Moonrise, Moonset and Meridian Passing Times Calculator – Timehubzone (2024)

FAQs

How do you know when the Moon passes the meridian? ›

When we use the word meridian, it usually refers to the moment that the Moon crosses or passes a location's meridian; this marks the exact moment when the Moon reaches the highest position in the sky.

By subtracting the hour angle of the rising point from the local time of culmination of the rising point, we obtain the time (local to the station) of moonrise. By adding the hour angle of the setting point to the local time of culmination of the setting point we obtaii~ the time (local to the station) of moonset.

The exact times depend on the lunar phase and declination, as well as the observer's location. As viewed from outside the polar circles, the Moon, like all other celestial objects outside the circumpolar circle, rises from the eastern half of the horizon and sets into the western half due to Earth's rotation.

Moonrise (and, incidentally, the time of high tide) occurs about 50 minutes later each day than the day before. To determine the moonrise time for each day of the month, add 50 minutes each day after a phase or subtract 50 minutes each day before a new phase.

Period of the orbit is about 27.3 days. This is called the SIDERIAL PERIOD or SIDEREAL MONTH. This is measured with respect to the background stars: the moon takes 1 sidereal period to cycle around once. In its eastward motion, the moon stays near the ecliptic.

The moon takes about 27.3 days to revolve round the earth in a nearly circular orbit of radius 3.84×105 km.

Time moves a bit faster on the moon than on Earth because the moon's mass is smaller than that of Earth and its gravity is weaker. That means the moon is going to get its own time zone. NASA has been asked to establish a unified standard time for the moon and other celestial bodies by the end of 2026.

A day on the Moon is 27.32 Earth days or 655.72 hours long.

The way the Moon looks to us is continually changing. It moves across the sky rapidly over the course of a night. And from night to night it rises and falls at different times and in different parts of the sky.

What determines moonrise and moonset? ›

It is the Earth's rotation on its axis that makes the moon rise in east and set in the west. The picture below is of the moon setting in the west behind the Sierra Nevada mountains in the morning.

That happens because of the tilt of the Earth and its position to both the sun and moon. We can see them simultaneously, but not necessarily as one sets and the other rises.

The Full Moon rises at sunset. The Full Moon rises at sunset and can be seen against a starry night sky. The side of the Moon facing Earth can be seen to be fully illuminated by the Sun. The Full Moon sets early in the morning as the sun is rising.

The lunar cycle is predictable. The new moon always rises with the Sun in the morning, the first quarter rises around noon, the third quarter rises at midnight, and the full moon rises as the Sun sets in the evening.

At midnight the local zenith points into space on the side of Earth away from the Sun. The meridian passes from pole to pole through the zenith, so the Moon, when it crosses this line, is also on the side of Earth away from the Sun: full moon.

If the Moon does not pass through the meridian on a given date, the columns are empty. This occurs once every Moon cycle.

The longitude gives the position east or west of the Moon's prime meridian, which is the line passing from the lunar north pole through the point on the lunar surface directly facing Earth to the lunar south pole. (See also Earth's prime meridian.)