space mercury

Mercury is the smallest and innermost planet in the Solar System. Its orbital period around the Sun of 88 is the shortest of all the planets in the Solar System. It is named after the Roman deity, the messenger to the gods.

Like Venus, Mercury orbits the Sun within Earth's orbit as an inferior planet, so it can only be seen visually in the morning or the evening sky, and never exceeds 28° away from the Sun. Also, like Venus and the Moon, the planet displays the complete range of phases as it moves around its orbit relative to Earth. Seen from Earth, this cycle of phases reoccurs approximately every 116 days, the so-called synodic period.

Although Mercury can appear as a bright star-like object when viewed from Earth, its proximity to the Sun often makes it more difficult to see than Venus.