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 …

5 days ago · The Earth and Moon are tidally locked. Their rotations are so in sync we only see one side of the Moon. Humans didn't see the lunar far side until a Soviet spacecraft flew past in 1959. The …

4 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 …

Dec 4, 2025 · What's the Moon's phase today? With our 2025 Moon Phase Calendar, you'll find the current Moon phase for tonight—plus, all the phases of the Moon for each day of the month.

1 day ago · Check the Moon phase today with our live Moon Phase Tracker. See if it’s a Full Moon, New Moon, or Crescent in real time.

Find the Moon’s illumination, distance, and latitude for any time on any date. The Moon has four primary and four intermediate lunar phases during a lunar month. Here's all you need to know about each …

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 …

The Moon Returning humans to lunar missions Why the moon? The Moon is one of Earth's closest habitable neighbors and provides an opportunity to gain valuable experience for missions to Mars …

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.

4 days ago · Humans haven’t been back to the lunar surface since the Apollo moon program ended over five decade ago. The reasons why go beyond science, according to experts.