In geophysical terms, the Moon is a planetary-mass object or satellite planet. Its mass is 1.2% that of the Earth, and its diameter is 3,474 km (2,159 mi), roughly one-quarter of Earth's (about as wide as the …

Dec 29, 2025 · Like Earth, the Moon has a day side and a night side, which change as the Moon rotates. The Sun always illuminates half of the Moon while the other half remains dark.

3 days ago · Discover fascinating Moon facts—from its size and orbit to gravity, brightness, and temperature. Learn what makes Earth’s Moon truly unique.

We see the full moon when the sun is directly behind us, illuminating a full hemisphere of the moon when it is directly in front of us.

Jan 13, 2026 · Particles from Earth’s atmosphere have been carried into space by solar wind and landing on the moon for billions of years, mixing into the lunar soil, according to a new study.

What is the moon made of, and how did it form? Learn about the moon's violent origins, how its phases shaped the earliest calendars, and how humans first explored Earth's only natural satellite half a …

3 days ago · Moon, Earth’s sole natural satellite and nearest celestial body. Known since prehistoric times, it is the brightest object in the sky after the Sun. Its name in English, like that of Earth, is of …

Find tonight's moon, moonrise, moonset, moon phases, cycles, and much more...

The moon is the Earth's only natural satellite and the closest celestial object. Learn about the moon and some of the theories about the moon's origin.

9 hours ago · The long road to launching Artemis 1 will help in preparing to bring four astronauts around the moon as soon as Feb. 6, NASA said.