full moon
A time when the Moon looks like a full bright circle.
A full moon occurs when the Moon appears as a complete, bright circle in the night sky. This happens about once every 29 days, when the Moon is on the opposite side of Earth from the Sun, allowing sunlight to illuminate the entire face of the Moon that we can see.
The Moon doesn't make its own light: it reflects the Sun's light like a giant mirror in space. As the Moon orbits Earth, we see different amounts of its sunlit side, creating what we call phases. During a full moon, we see the whole sunlit half, making it the brightest Moon phase. On a clear night, a full moon can be so bright that it casts shadows and you can almost read by its light.
Full moons have captivated people throughout history. Many cultures gave names to each month's full moon: the Harvest Moon in autumn helped farmers work late into the evening, while the Wolf Moon in January supposedly got its name from wolves howling in winter.
The Moon's gravity pulls on Earth's oceans, creating tides. During a full moon, when the Sun, Earth, and Moon align, tides are especially strong. Some people believe full moons affect human behavior, though scientists have found little evidence for this. What's certain is that a full moon rising over the horizon remains one of nature's most beautiful sights.