Earth referred to as "moons", after Earth's. The gravitational attraction between Earth and the Moon causes tides on Earth. The same effect on the Moon has led to its tidal locking: its rotation period is the same as the time it takes to orbit Earth. As a result, it always presents the same face to the planet. As the Moon orbits Earth, different parts of its face are illuminated by the Sun, leading to the lunar phases; the dark part of the face is separated from the light part by the solar terminator. Due to their tidal interaction, the Moon recedes
Gravitation of the Moon Gravitation of the Moon The acceleration due to gravity on the surface of the Moon is about 1.625 m/s, about 16.6% that on Earth's surface or 0.166 . Over the entire surface, the variation in gravitational acceleration is about 0.0253 m/s (1.6% of the acceleration due to gravity). Because weight is directly dependent upon gravitational acceleration, things on the Moon will weigh only 16.6% of what they weigh on the Earth. The gravitational field of the Moon has been measured by tracking the radio signals emitted by orbiting spacecraft. The principle used depends on the Doppler effect, whereby the line-of-sight