How Long Does Earth Rotate Around the Earth-Moon Barycentre?

[freedom6446]

The question is about the Earth's rotation and duration.

It is my understanding that the Earth and moon rotate around the earth-moon system common center of gravity (also known as the barycentre).

Question #1. How long does it take for the Earth to complete one full turn around the earth-moon system barycentre?

Question #2. In addition to the Earth rotating around the earth-moon system barycentre, does the Earth also rotate about its own center axis?

Any feedback would be greatly appreciated. Thanks in advance!

 

[SteamKing]

The answer to question 2: it's called a day.

 

[Nik_2213]

And the answer to #1 --To a first approximation-- is a lunar month...

Then you must decide what a 'full turn' represents given the Earth/Moon system orbits Sun, and the orbits are slightly elliptical etc etc...

 

[Drakkith]

The question is about the Earth's rotation and duration.

It is my understanding that the Earth and moon rotate around the earth-moon system common center of gravity (also known as the barycentre).

Question #1. How long does it take for the Earth to complete one full turn around the earth-moon system barycentre?

Question #2. In addition to the Earth rotating around the earth-moon system barycentre, does the Earth also rotate about its own center axis?

Any feedback would be greatly appreciated. Thanks in advance!

1. From wikipedia on the moon: The Moon makes a complete orbit around the Earth with respect to the fixed stars about once every 27.3 days (its sidereal period). However, since the Earth is moving in its orbit about the Sun at the same time, it takes slightly longer for the Moon to show the same phase to Earth, which is about 29.5 days

So the time it takes for the Earth AND the moon to make one revolution around their barycenter is about 27.3 days.

2. Yep. It rotates around its own axis approximately once every 24 hours.