Explanation:
What are those lights and shadows crossing the Earth?
As the featured five-second
time-lapse video
progresses, a full day on planet Earth is depicted as seen from
Japan's
Himawari-8 satellite in
geostationary orbit high above the
Pacific Ocean.
The Sun rises to the right and sets to the left,
illuminating the
half of Earth that is most directly below.
A reflected image of the Sun -- a
Sun glint --
is visible as a bright spot that moves from right to left.
More unusual, though, is the
dark spot that moves from the lower left to upper right
That is the
shadow of the Moon,
and it can only appear when the Moon goes
directly between the Earth and the Sun.
Last year, on the day these images were taken, the most deeply shadowed
region experienced a
total eclipse of the Sun.
Next month
a similarly dark shadow will sweep
right across the USA.
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