Heliocentric and Moon's motion

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In summary, the Moon's trajectory in a heliocentric reference is not a perfect circle, but a shallow sine wave approximately 67 million km long and 768,000 km wide. Its mean speed in this reference frame is about 30 km/sec.
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termina
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Hello there!


We know that in geocentric reference, Moon's trajectory is roughly a circle and moves at a mean speed of 3680km/hour.

But, from a heliocentric frame of reference,
Moon's trajectory in 1 sideral period isn't a circle but a curvature.

[PLAIN]http://img22.imageshack.us/img22/6411/mmneg.jpg


Since Moon's circle orbit revolves around the Sun as the Moon revolves around our planet,
Moon's speed from Sun's viewpoint may be different from 3680km/h.

So, my question is:

how long is this curvature in km? What's the MEAN speed of the Moon in heliocentric reference?


Thank you
 
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  • #2
In one sidereal month, the Earth travels about 67 million km. The Moon's heliocentric path would be a approximately be a shallow sine wave 67 million km long and 768,000 km wide from peak to peak.( It would be some 87 times longer than the peak to peak thickness.)

The mean heliocentric velocity would be equal to that of the Earth's orbital velocity, or ~30 km/sec.

In addition, the curvature of the Moon's heliocentric path would always be towards the Sun.
 

1. What is heliocentric motion?

Heliocentric motion refers to the idea that the Earth and other planets in our solar system revolve around the Sun. This theory was first proposed by ancient Greek philosopher Aristarchus and was later supported by Copernicus, Kepler, and Galileo.

2. How does heliocentric motion differ from geocentric motion?

In geocentric motion, the Earth is believed to be the center of the universe and all celestial bodies, including the Sun, revolve around it. This theory was widely accepted before the heliocentric model was introduced.

3. How was the heliocentric model of the solar system proven?

Galileo's observations using a telescope provided evidence for heliocentric motion. He observed the phases of Venus, the moons of Jupiter, and the changing positions of the stars, all of which supported the idea of a Sun-centered solar system.

4. What is the Moon's motion in relation to the Earth?

The Moon orbits around the Earth in an elliptical path. This motion is caused by the gravitational pull of the Earth, and it takes the Moon approximately 27 days to complete one orbit.

5. Why do we see different phases of the Moon?

The Moon's phases are a result of its position relative to the Sun and Earth. As the Moon orbits the Earth, the amount of sunlight hitting its surface changes, causing the different phases we observe on Earth.

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