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ORBONIX · EARTH'S MOON
MOON
Earth's only natural satellite and the
closest major celestial body to our planet.
MOON · EARTH'S NATURAL SATELLITE
384,400 km
AVERAGE DISTANCE FROM EARTH
3,475 km
DIAMETER
27.3 DAYS
ORBITAL PERIOD
27.3 DAYS
ROTATION PERIOD
1.62 m/s²
SURFACE GRAVITY
−173°C → 127°C
APPROX. SURFACE TEMPERATURE
EARTH'S MOON
The Moon is Earth's only natural satellite
and the fifth-largest moon in the Solar System.
Its surface is covered with impact craters,
mountains, valleys and enormous ancient
basins created by collisions with asteroids
and other objects.
The Moon is tidally locked to Earth. This
means that it rotates once on its axis in
approximately the same amount of time that
it takes to orbit Earth.
As a result, the same side of the Moon
always faces our planet.
TIDALLY LOCKED
The Moon rotates once for every orbit
around Earth, so we normally see the
same hemisphere.
NO THICK ATMOSPHERE
The Moon has an extremely thin exosphere,
so its surface is exposed directly to
space.
WATER ICE
Water ice exists in permanently shadowed
regions near the lunar poles.
DID YOU KNOW?
The Moon is slowly moving away from Earth
at roughly 3.8 cm per year.
WHY THE MOON MATTERS
The Moon preserves a geological record extending back billions of years. With little atmosphere, no liquid-water weather and limited ongoing geological resurfacing, many ancient impact structures remain visible. Samples returned by lunar missions have helped scientists reconstruct the history of the Moon and the early Solar System.
The Moon also affects Earth through gravity, most visibly by driving ocean tides. Its proximity makes it an important destination for robotic science, human exploration and testing technologies for missions farther from Earth.
IMAGE:
NASA / WIKIMEDIA COMMONS