*As well as being the closest planet to the sun, Mercury (4,878km wide) is also the smallest planet in the solar system, similar in size to our Moon (3475.6km wide) and 2/5 the size of Earth.
*Mercury orbits the Sun quicker than all other planets in our solar system with its speed caused by the Sun’s powerful gravitational pull. The planets quick motion through the sky has seen it associated with Mercury, the speedy messenger of the gods from Roman mythology.
*A year on Mercury is around 88 days long, but one full day (from sunset to sunrise) takes 176 days.
*Mercury has an iron core, and has a magnet field strong enough to repel the solar winds. Its wrinkled surface features, known as Lobate Scarpes, are a result of the cooling and contraction of its core, with its many craters formed after numerous encounters with asteroids and comets.
*Mercury is known as the “elusive planet” because its close proximity to the Sun doesn’t allow for night time viewing. As the Sun sets so does Mercury, therefore it is best viewed an hour before sunrise or sunset from the Earth’s perspective. When observed through a telescope, Mercury can be seen going through phases like the Moon and appears as a bright, blue spot of light.
*Mariner 10 passed by Mercury three times from 1974 to 1975 and managed to map around 45% of the planet’s surface.