panoramic night scene from June 8
looks out across a Moscow skyline from atop the
main building of
Lomonosov Moscow State University.
Shining in the darkened sky above are widespread
From the edge of space, about 80 kilometers above Earth's surface,
the icy clouds can still reflect sunlight even though the Sun itself is
below the horizon as
seen from the ground.
Usually spotted at
latitudes in summer months the diaphanous
apparitions, also known as polar mesospheric clouds,
have come early this season.
The seasonal clouds are understood to form as water vapor driven
into the cold upper atmosphere condenses on the fine dust particles
(debris left by disintegrating meteors) or
Their early start this year may be connected to changing
global circulation patterns in the lower atmosphere.
During this northern summer, NASA's AIM mission provides
daily projections of the noctilucent
seen from space.