What’s creating this giant hole in space?
This is not a
black hole — it’s a shadow.
It’s
Earth’s shadow.
Since at least the time of
Aristotle,
people have noted that
Earth's dark shadow on the
Moon during a partial
lunar eclipse is circular -- although never a
whole circle.
Using
modern digital technology, though,
the images of multiple
lunar eclipses can be combined to show Earth's complete shadow.
The
featured image compilation by a perseistent astrophotographer
is constructed from 22 years of lunar eclipses.
The Moon is not
eclipsed every month
(
moon-th) because the
Moon's orbit is
slightly tilted relative to Earth's orbit.
Close inspection of some lunar eclipse images shows a
faint
blue
band where
Earth’s atmosphere filters out more red sunlight than blue.
Later this week, a
new lunar eclipse will occur and will be
best visible in parts of North and South America, Europe, and Africa.