At the Shadow's Edge
Image Credit &
Copyright:
Jean-Francois Gout
Shaped like a cone tapering into space, the Earth's dark
central shadow or umbra
has a circular cross-section.
It's wider than the Moon at the distance of
the Moon's orbit though.
But
during the lunar eclipse
of November 18/19, part of
the Moon remained just outside the umbral shadow.
The successive pictures
in this composite of 5 images from that
almost total lunar eclipse
were taken over a period of about 1.5 hours.
The series is aligned to trace part of the cross-section's
circular
arc, with the central image at maximum eclipse.
It shows a bright, thin sliver of the lunar disk still beyond
the shadow's curved edge.
Of course, even within the shadow the Moon's surface is not completely
dark, reflecting the reddish hues of filtered sunlight scattered
into the shadow by Earth's atmosphere.