All objects in the solar system, including the Moon, get their light from the sun. The Moon has no light of its own. It shines because its surface reflects light from the sun. At any time, half of the Earth and half of the Moon are lit by the sun. The brightness of the Moon from the Earth depends on where the moon is in its orbit around the planet. The Moon travels once around the Earth every 29.5 days. During its journey, it is lit from different angles by the sun.