Moon- nodes.

The lunar orbit plane is inclined to the ecliptic by 5.1°.

The ecliptic is the apparent path of the Sun over a year, on the celestial sphere as seen from the Earth's centre.

Because the paths of the sun and moon are at an angle to each other, the moon crosses the path of the Sun twice,  each time the moon goes once around the earth..once every month.

These points of crossing are called, lunar nodes, and they precess gradually westward, performing a complete circle in approximately 18.6 years: a draconitic or nodical period.

This screen shot from Stellerium shows the position of the Moon tonight.

• The Equator is an imaginary line 90 degrees to the Meridian.
• The Meridian runs North-South.
• The Equator runs East-West.

Tonight the Moon is below the ecliptic.
This means that the Moon is low in the sky, and looks bigger.

On the 4th of March the Moon is on the ecliptic.

On the 11th March the Moon is above the ecliptic.

And on the 15th of March, the Moon is again, crossing the ecliptic.

Now it is fairly obvious that the Moon moves above, and then below the ecliptic, something like every two weeks.

And the angle of the Moon with respect to the ecliptic, changes the position the Moon is seen rising from: its azimuth.

• Solar eclipses occur when a new Moon crosses a node.
• Lunar eclipses occur when full moon crosses a node.
• And the moon only rises in the same place at the same day and month, every 18.6 years.

To read about Major and Minor Lunar Standstill, continue...