: Is it truly correct to say that the Earth orbits the sun?? Wouldn't it be more truthfull to say that the Earth orbits a common center of gravity shared by not only the Earth and the sun, but all other planets in between. Being technical then, we don't orbit the sun, we orbit the sun and the inner planets. (which could offset our orbit by maybe a few miles or so from the actual sun's center of gravity).

Wayne: CL, yes you are correct. Our galaxy has a center of gravity around which our solar system and all others in the galaxy orbit. Our solar system also has its own center of gravity which will orbit the suns center of gravity. (I believe this could be another way to explain the shift in Mercury's orbit) I don't recall ever reading any research on locating and tracking systemic centers of gravity such as the one our solar system has. Or the one shared by the earth and the moon. Example: The center of gravity for the earth and the moon would be a point inside the earth, but nearer the earth crust on the moon side. A balance point with 50% of the total mass of both bodies, located on each side of that point. This shared point (center of gravity) would orbit the earth's center of gravity. SO, all bodies in the system will have more than one orbital path. The primary path around the galaxy center is one of its orbits, and the obital path it takes around the sun would have a corkscrew look to it when seen by observers from another galaxy.