Named after the fleet footed messenger of the Roman Gods, Mercury is the smallest and closest planet to the Sun, thus having the shortest orbital period of 88 days.

The orbit of Mercury has a relatively large eccentricity of 0.206 so the distance from the sun varies from 0.307 to 0.466 AU (46 to 70 million kilometers).

Similar to Venus, as Mercury’s orbit is inside that of Earth’s it is only ever visible in the evening or early morning and also displays phases as it orbits relative to Earth.