B Question about the Sun's gravitational influence on the Earth and its moon

[Evenlander]

If the sun has a gravitational influence on Earth and on its moon then why isn't the moon revolving around the sun. If the gravitational force of sun is large enough to make planets like Jupiter revolve around it (which has a greater mass than that of the moon.) Why not moon?

 

[PeroK]

If the sun has a gravitational influence on Earth and on its moon then why isn't the moon revolving around the sun. If the gravitational force of sun is large enough to make planets like Jupiter revolve around it (which has a greater mass than that of the moon.) Why not moon?

What makes you think the Moon is not orbiting the Sun?

 

[BvU]

Hello Evenlander, !

Earth and moon orbit around a common center of gravity. That center of gravity orbits around the sun. Matter of initial conditions and Newtons law of gravity. Once the orbits are stable there 's a lot of momentum needed to change them.

Jupiter has moons too

 

[Evenlander]

What makes you think the Moon is not orbiting the Sun?

I never thought about this. Thanks.

 

[A.T.]

I never thought about this. Thanks.

https://en.wikipedia.org/wiki/Orbit_of_the_Moon#Path_of_Earth_and_Moon_around_Sun

 

[Dale]

https://en.wikipedia.org/wiki/Orbit_of_the_Moon#Path_of_Earth_and_Moon_around_Sun

@Evenlander note this quote from the above page:

“The Sun's gravitational effect on the Moon is more than twice that of Earth's on the Moon; consequently, the Moon's trajectory is always convex[24][25] (as seen when looking Sunward at the entire Sun–Earth–Moon system from a great distance outside Earth–Moon solar orbit)”

 

[A.T.]

@Evenlander note this quote from the above page:

“The Sun's gravitational effect on the Moon is more than twice that of Earth's on the Moon; consequently, the Moon's trajectory is always convex[24][25] (as seen when looking Sunward at the entire Sun–Earth–Moon system from a great distance outside Earth–Moon solar orbit)”

And the Figure:
https://en.wikipedia.org/wiki/Orbit_of_the_Moon#/media/File:Moon_trajectory1.svg

 

[russ_watters]

I never thought about this. Thanks.

To be more specific, the Earth-moon system's orbit around the sun is 149.6 +/- 0.5 million km in radius (it's elliptical). The moon is 0.36 million km from Earth, or about 0.2% of that distance. If you animated that and deleted the Earth, you probably wouldn't even notice the wobble in the moon's orbit around the sun.

 

[sophiecentaur]

you probably wouldn't even notice the wobble in the moon's orbit around the sun.

Around +/- 0.2% of wobble (about 300 thousand km in 150 million km), with about 13 cycles of 'wobble' on the way round. It never 'goes backwards' in its orbit round the Sun.
There are three body systems where the 'moon' body has a horseshoe orbit around the 'sun' body, whilst more or less following the orbital path of the 'earth' body. That link can be initially confusing.