After Pluto, Mercury has the most elliptical orbit of any planet in the solar system.

Point in Orbit | Published distance in km (000) |
Relative distance where Mercury = 1 |

Perihelion | 46.0 | 0.7945 |

Mean | 57.9 | 1.0000 |

Aphelion | 69.8 | 1.2065 |

As with all the other planetary distances that involve a relationship in the form ½ ( √x + y ), the same relationships exist in the orbit of Mercury:

Point in Orbit | Published distance in km (000) |
As expressed in Solar Geometry |
Resulting numeric value |
Difference from published value above |

Perihelion | 46.0 | 2- ½ (√2+1) | 0.7929 | 0.0016 |

Mean | 57.9 | ½ (√1+1) | 1.0000 | 0.0000 |

Aphelion | 69.8 | ½ (√2+1) | 1.2071 | -0.0016 |

Again, Solar Geometry explains the orbits of the solar system with a relationship that appears again and again.

This results in the following Solar Geometry, show the aphelion (A), mean (Mercury) and perihelion (P) of Mercury’s orbit in relation to the Sun. Note that the perihelion is half way between the mean orbital distance of 1 and radius of the square, which is the square root of 2.