Mercury
Mercury is the smallest and closest planet to the sun in the Solar System. Its orbit around the Sun takes 87.97 Earth days, the shortest of all the planets in the Solar System. It is named after the Greek god Hermes (Ερμής), translated into Latin as Mercurius (Mercury), god of commerce, messenger of the gods, mediator between gods and mortals.
Like Venus, Mercury orbits the Sun within Earth's orbit as an inferior planet, and its apparent distance from the Sun as viewed from Earth never exceeds 28°. This proximity to the Sun means the planet can only be seen near the western horizon after sunset or eastern horizon before sunrise, usually in twilight. At this time, it may appear as a bright star-like object, but is often far more difficult to observe than Venus.
Mercury Facts
- Diameter: 4,879 km
- Mass: 3.29 × 10^23 kg (0.06 Earths)
- Moons: None
- Orbit Distance: 57,909,227 km (0.39 AU)
- Orbit Period: 88 days
- Surface Temperature: -173 to 427°C
- First Record: 14th century BC
- Recorded By: Assyrian astronomers