Details: This poster shows a full moon against the dark night sky.
The Moon is Earth's only natural satellite and the fifth largest satellite in the Solar System. The average centre-to-centre distance from the Earth to the Moon is 384,403 km, about thirty times the diameter of the Earth. The Moon makes a complete orbit around the Earth every 27.3 days[nb 3] (the orbital period), and the periodic variations in the geometry of the Earth-Moon-Sun system are responsible for the phases of the moon, which repeat every 29.5 days[nb 4] (the synodic period). The Moon's diameter is 3,474 km, a little more than a quarter of that of the Earth. Thus, the Moon's surface area is less than a tenth that of the Earth, and its volume is about 2 percent that of Earth.
This poster is usually printed with a thin white edge border.