Meeting in the Mesosphere
Explanation:
A sensitive video camera on a summit of the Vosges mountains in France
captured these surprising fireworks above a
distant horizon
on June 26.
Generated
over intense thunderstorms,
this one about 260 kilometers away,
the brief and mysterious flashes have come to be known as red sprites.
The transient luminous events are caused by electrical breakdown
at altitudes of 50 to 100 kilometers.
That
puts them in the mesophere,
the coldest layer of planet Earth's atmosphere.
The glow beneath the sprites is from more familiar lighting
though, below the storm clouds.
But on the right, the video frames have captured
another summertime apparition from the mesophere.
The silvery veins of light
are polar mesospheric clouds.
Also known as noctilucent or night shining clouds, the icy clouds still
reflect the sunlight
when the Sun is below the horizon.
Authors & editors:
Robert Nemiroff
(MTU) &
Jerry Bonnell
(USRA)
NASA Web Site Statements, Warnings,
and Disclaimers
NASA Official: Jay Norris.
Specific
rights apply.
A service of:
LHEA at
NASA /
GSFC
& Michigan Tech. U.
