No atmosphere, no liquid water, and extreme temperature swings
• Composed mainly of oxygen, silicon, magnesium, iron, calcium, and aluminum
Diameter: ~3,474 km (about 27% of Earth’s diameter)
• Average Distance from Earth: ~384,400 km
Orbital Period: ~27.3 days (sidereal); ~29.5 days (synodic, full moon to full moon)
• Tidal Locking: The Moon rotates once per orbit, so we always see the same face—its far side remained unseen until 1959.
• Its orbit is elliptical, not perfectly circular, causing variations in apparent size (supermoon vs micromoon).
When the Sun shines directly on the Moon’s surface, temperatures can reach up to 127°C (260°F).
When the Sun sets, temperatures plummet to around –173°C (–280°F).