Mercury (planet) Mercury (planet) Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 87.97 days is the shortest of all the planets in the Solar System. It is named after the Roman deity Mercury, the messenger of the gods. Like Venus, Mercury orbits the Sun within Earth's orbit as an "inferior planet", and never exceeds 28° away from the Sun. When viewed from Earth, this proximity to the Sun means the planet can only be seen near the western or eastern horizon during the early evening or early morning. At this time it
The empire on which the sun never sets The empire on which the sun never sets The phrase "the empire on which the sun never sets" has been used with variations to describe certain global empires that were so extensive that there was always at least one part of their territory that was in daylight. It was originally coined for the Spanish Empire, mainly in the 16th and 17th centuries. In more recent times, it was used for the British Empire, mainly in the 19th and early 20th centuries. During this period, the British Empire reached a territorial size larger than that of any other empire in history.