Earth & Space
Why Do Tides Happen?
Tides happen because the moon's gravity pulls on Earth's oceans unevenly, creating two tidal bulges that coastlines rotate through each day.
tidesmoon
Space & Astronomy
Why Can We See the Moon During the Day?
The moon is visible during the day because it reflects enough sunlight to stand out against the blue sky, depending on its phase and position.
moondaytime moon
Space & Astronomy
Why Does the Moon Change Shape?
The moon does not actually change shape. Its phases are caused by the changing angle at which we see its sunlit half as it orbits Earth.
moonlunar phases
Space
Why Is Gravity Weaker on the Moon?
Gravity is weaker on the moon because the moon has much less mass than Earth. Less mass means less gravitational pull, so objects weigh about one-sixth of what they do on Earth.
spacemoon mass