The Moon (also called Luna) is Earth’s only natural satellite.
It formed about 4.5 billion years ago, roughly 30–50 million years after the formation of the solar system. The Moon is in synchronous rotation with Earth, meaning the same side always faces our planet. The first uncrewed mission to the Moon was launched in 1959 by the Soviet lunar program, while the first crewed landing occurred in 1969 during Apollo 11.
Moon Profile | |
|---|---|
Equatorlal Diameter | 3,474 km |
Polar Diameter | 3,472 km |
Mass | 7.35 × 10²² kg (≈ 0.012 Earths) |
Orbit Distance | 384,400 km (from Earth) |
Orbit Period | 27.3 Earth days
(Sidereal month) |
Surface Tempature | −173 °C to 127 °C |
Atmosphere | Extremely thin exosphere
(Helium, neon, argon, hydrogen) |
Surface Gravity | 1.62 m/s² (≈ 16.5% of Earth) |
First Record | Prehistoric |
Recorded By | Human civilizations worldwide |
In astrology, the Moon is the ruler of Cancer.
It represents our deepest personal needs, habitual responses, emotional instincts, and the unconscious patterns that shape how we react to the world.
Both sides of the Moon receive equal amounts of sunlight. However, only one side is visible from Earth because the Moon rotates on its axis at the same rate it orbits Earth. The far side remained unseen by humans until spacecraft explored it.
The Moon’s gravitational pull creates two tidal bulges on Earth, one facing the Moon and one on the opposite side. As Earth rotates, these bulges move across the oceans, producing regular high and low tides worldwide.
The Moon moves away from Earth at a rate of about 3.8 cm per year. Over billions of years, this will lengthen Earth’s days and cause the Moon’s orbit to slow.
Because the Moon’s gravity is much weaker, you would weigh about one-sixth (16.5%) of your Earth weight. This reduced gravity allowed astronauts to leap and move with ease.
All were American astronauts. The first was Neil Armstrong in 1969 during Apollo 11, and the last was Gene Cernan in 1972 on Apollo 17. Since then, only robotic missions have visited the Moon.
Without an atmosphere, the Moon is exposed to solar wind, cosmic radiation, and meteorite impacts. Temperatures vary drastically, sound cannot travel, and the sky appears permanently black.
Moonquakes are caused mainly by Earth’s gravitational pull. Instruments left by astronauts detected seismic activity deep beneath the surface, suggesting the Moon may still have a partially molten core.
The Soviet spacecraft Luna 1 passed within about 6,000 km of the Moon before entering orbit around the Sun, marking humanity’s first close encounter with another world.
With a diameter of 3,475 km, it is smaller than several moons of Jupiter and Saturn. A leading theory suggests the Moon formed after a massive collision between Earth and a Mars-sized object early in the solar system’s history.
Space agencies aim to send astronauts back to the Moon in the coming decades, with plans that include long-term research bases and preparation for future missions deeper into space.
During the Cold War, the United States studied a classified plan known as Project A119, which proposed detonating a nuclear device on the Moon as a show of power. The idea was never carried out.
