|Gravity||0.38 g (3.7 m/s²)|
|Primary Terrain||Rocky deserts, craters|
|Surface water||Water-ice in polar craters|
|Rotation period||58.6 Earth days|
|Orbital Period||88 Earth days|
Because of its proximity to its parent star and near absence of liquids or gases, Mercury's surface undergoes extreme temperature variations between day and night and is currently considered an unlikely location for life. Compared to Venusians, Martians or even Jovians; Mercurians are a rarity in science fiction and are typically described as rather simple lifeforms, one exception being the humanoid Mercurians from DC.
Mercury is the planet closest to the Sun.