Sprites from Space
Image Credit:
NASA,
Expedition 44
An old Moon
and the stars of Orion rose above the eastern horizon
on August 10.
The Moon's waning crescent was still bright enough
to be overexposed in this
snapshot
taken from another large satellite
of planet Earth, the International Space Station.
A greenish airglow traces the atmosphere above the limb of
the planet's night.
Below, city lights and lightning flashes from thunderstorms
appear over southern Mexico.
The snapshot also captures the startling apparition
of a rare form of upper atmospheric lightning, a large
red sprite caught
above a lightning flash at the far right.
While the space station's orbital motion causes the
city lights to blur and trail during the exposure,
the extremely brief flash of the red sprite is sharp.
Now known to be associated with thunderstorms,
much remains a mystery about sprites including how they occur,
their effect on the atmospheric
global electric circuit,
and if they are somehow related to other
upper atmospheric lightning
phenomena such as blue jets or
terrestrial gamma flashes.