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 17, 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 in 1959. …

Dec 26, 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 of Earth, is of …

Nov 6, 2025 · Earth's atmosphere leaks all the way out to the moon. Anomalous amounts of volatile elements found in the Apollo samples brought back from the moon have been traced back to our …

6 days ago · If all goes according to NASA’s plans, 2026 will finally be the year that astronauts once again launch to the moon. In a matter of months, four astronauts are poised to fly around the moon …

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 …

2 days ago · The NASA Artemis II mission, set to lift off as soon as February, will mark the first time astronauts have aimed to venture beyond near-Earth orbit since 1972.

4 days ago · The moon and sun share top billing in 2026. Kicking off the year's cosmic wonders is the moon, drawing the first astronauts to visit in more than 50 years.

Mar 6, 2025 · Order Your Almanac Today! Never miss a full moon, eclipse, or meteor shower with reminders from the Almanac Daily newsletter.

Dec 23, 2025 · When does the next full moon rise? Find out exactly when to see the full moons of 2026, including the full "Wolf Moon" supermoon in January.