Explanation:
Earth's Moon
is normally seen in subtle shades of grey or yellow.
But small color differences
have been greatly exaggerated
to make this dramatic mosaic image of
the Moon's gibbous phase.
The familiar Sea of Tranquility
(Mare Tranquillitatis) is the blue area right
of center.
White lines radiate
from the crater Tycho at bottom left,
while purplish tones mottle the crater
Copernicus left of center.
Though exaggerated, the different colors are recognized to
correspond to real differences in
the chemical makeup of the lunar surface - blue
hues reveal
titanium rich
areas while orange and purple colors
show regions relatively poor in titanium and iron.
Calibrated by
rock samples
from the Apollo missions, similar multicolor
images from spacecraft
have been used to explore
the Moon's
global surface composition.
