Explanation:
This surreal, wintry scene
is a composite picture
recorded
on December 10 as the Moon
rose behind the Zagros Mountains of Iran.
A total lunar eclipse was already
in progress.
The image combines nearly 500 successive frames taken
over 1.5 hours beginning
in twilight as the eclipsed Moon steadily
climbed above the rugged landscape.
The reddened lunar disk and deep blue twilight make for a striking
contrast, yet the contrasting colors have the same root cause.
The eclipsed Moon is red because the
Earth's
umbral shadow is suffused with
a faint red light.
The ruddy illumination is from all the
reddened sunsets and sunrises, as seen from a
lunar perspective.
But the sunsets and sunrises are reddened because
the Earth's atmosphere
scatters blue
light more strongly
than red, creating the twilight sky's dim, blue glow.
