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 …

Jun 25, 2025 · 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 …

Dec 11, 2025 · 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 …

• By measuring the ages of lunar rocks, we know that the moon is about 4.6 billion years old, or about the same age as Earth. • The distance between the Earth and its moon averages about...

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 …

Dec 4, 2025 · 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.

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 …

Sep 7, 2023 · How big is the Moon? The Moon is Earth’s only permanent natural satellite, and it’s the fifth-largest satellite in our solar system. The Moon’s diameter is approximately 2,160 miles …

Jul 7, 2025 · It orbits the Earth at an average distance of approximately 240,000 miles (384,000 km). The Moon completes an orbit of the Earth every 27.3 days (approximately 655 hours). …

Nov 6, 2025 · Research shows a full moon can modestly affect sleep, but its influence on mental health is much less certain.