A single pentagram, embodying the proportion known as the Golden Section, both spaces Earth and Mercury’s mean solar orbits and sizes their relative physical bodies with 99% accuracy. Coincidences between the proportions of two planets’ physical sizes and their mean orbits occur only twice in the solar system, and both involve Earth: between Earth and Mercury, and between Earth and Saturn. Coincidentally, Mercury and Saturn are the innermost and outermost of the medieval planets. The Golden Section is shown above defined by the arm-crossing of a pentagram (see Appendix 2.1 – the Golden Star)*. The unit "oo" means "our orbits" so that 1 oo = 149.5979 million km.

* Appendix 2.1 mentioned here is not currently available on celestial-sphere.