Explanation:
Tidally locked in
synchronous rotation,
the Moon always presents its
familiar nearside to
denizens of planet Earth.
From lunar orbit,
the Moon's farside can become familiar, though.
In fact
this sharp picture,
a mosaic from the Lunar Reconnaissance Orbiter's wide angle camera,
is centered on the lunar farside.
Part of a
global mosaic
of over 15,000 images acquired between November 2009 and February 2011,
the
highest resolution version shows features at a scale
of 100 meters per pixel.
Surprisingly, the
rough and battered
surface of the farside
looks very
different from the nearside covered with smooth dark lunar maria.
The likely explanation is that the
farside crust is thicker,
making it harder for molten material from the interior to flow to the
surface and form the smooth maria.
