P07 Barycentric balls Figure A1

A schematic diagram of the Earth-Moon system (not to scale), highlighting the position of the barycentre and the orbits of the Earth and Moon about this point. The barycentre is located around 4 650 km from the centre of the Earth – the radius of the Earth is just under 6 400 km. The barycentre is approximately 80 times further from the centre of the Moon than from the centre of the Earth.