what moon

The Moon is Earths only natural satellite, and it orbits at an average distance of 384,400 km (238,900 mi) from Earth, about 30 times the planets diameter. The Moon always presents the same side to Earth, because gravitational pull has locked its rotation to the planet. This results in the lunar day of 29.5 days matching the lunar month. The Moons gravitational pull, and to a lesser extent the Suns, are the main drivers of the tides. The Moon has four primary phases each month, and it takes about 29.5 days to complete one cycle of phases, known as a lunar cycle, lunation, lunar month, or synodic month. The four primary phases are the new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, and waning crescent. The Moon is a planetary-mass object or satellite planet, with a mass that amounts to 1.2% of Earths, and a diameter that is roughly one-quarter of Earths or with 3,474 km (2,159 mi) about as wide as Australia.