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What is the Orientation of the Moon’s Orbital Plane Relative to the Earth’s Equator?

-- John | October 15, 2025

Question:

Earth’s spin axis is tilted 22.5 degrees from the plane of its orbit around the sun. How about the moon? How is its orbital plane related to a plane thru Earth’s equator?
Reason: Suppose I wish to put a microwave dish at Earths pole(s). And keep it pointed at the moon. So that I could continually bounce a signal back to Earth. The dish would simply rotate on its polar axis at Earth’s 24-hr period plus the rate of the moon’s monthly revolution around us.
Q: But, will I also need to steer the dish in elevation to keep it centered on moon?

-- John

Answer:

The inclination of the Moon’s orbit relative to Earth’s equator varies, ranging from approximately 18.3 to 28.6 degrees over an 18.6-year cycle. This variation is due to the combination of the Moon’s orbit being tilted by about 5.15 degrees relative to the ecliptic (the Earth’s orbital plane) and the Earth’s axial tilt of about 23.4 degrees relative to the ecliptic. You will need to steer the antenna in elevation in order to keep it pointed at the Moon.

-- Jeff Mangum

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