Explanation:
What could cause such rays of dark?
Dark sky rays were caught in spectacular fashion earlier this month above
Utah,
USA.
The cause is something surprisingly familiar:
shadows.
Clouds near the horizon can block sunlight from
reflecting off air, making columns outward from the
Sun appear
unusually dark.
Cloud shadows can be thought
of as the complement of the more commonly highlighted
crepuscular rays, also visible above, where sunlight pours
though cloud holes.
Sometimes, on the opposite side of the sky,
anticrepuscular rays
can also be seen.
