The Moon Aligns Horizontally in the Sky Soon. This phenomenon occurs every 18.6 years when the Moon rises and sets at the most extreme points on the horizon, marking its highest and lowest positions in the sky.
Besides the total solar eclipse on April 8 and the dazzling auroras, there’s another wonderful event for sky watchers this year: “The Moon Aligns Horizontally in the Sky”, the first occurrence since 2006. During this event, the Moon rises and sets at the extreme northern and southern positions on the horizon, reaching its highest and lowest points in the 18.6-year lunar cycle.
The positions where the Moon rises and sets on the horizon change continuously. (Photo: Gianni Tumino).
This phenomenon occurs because the Moon does not follow the same path as the Sun. The positions where it rises and sets on the horizon change continuously due to the movements of the Earth and the Moon. The solar system is flat, with planets orbiting the Sun in the same plane, known as the ecliptic plane.
The Moon’s orbit is inclined at 5.1 degrees to the ecliptic, allowing it to rise and set within a range of 57 degrees in any given month. This explains why the Moon can sometimes rise and set at points on the horizon that are farther north and south compared to the Sun.
A phenomenon of the Moon standing still occurs when the tilt of both the Earth and the Moon is at its maximum. During this period, the Moon rises and sets at the extremes of its range. It rises at its highest point in the northeast and sets at its highest point in the northwest. During this time, it also rises in the extreme southeast and sets in the extreme southwest.
The horizontal alignment of the Moon occurs at night. The Moon rises farthest in the northeast in the Northern Hemisphere, flying higher in the sky and remaining in the sky for longer. It shines in a significantly different position compared to when the Moon is stationary, when the range of where it rises and sets is at its narrowest.
On June 21, the Sun will rise and set at the extreme northeastern and northwestern points, while the Strawberry Full Moon will rise and set at the northeastern and northwestern points.
To observe these phenomena, watch from the same location and you will notice a significant difference. It’s not necessary to have a pair of binoculars to see this effect, but they can help you zoom in to make the most of observing the Moon.
