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| Photo: Nightskyhunter.com |
I wandered
lonely as a cloud
That floats on
high o'er vales and hills,
When all at
once I saw a crowd,
A host, of
golden daffodils;
Beside the
lake, beneath the trees,
Fluttering and
dancing in the breeze.
Continuous as
the stars that shine
And twinkle on
the milky way,
They stretched
in never-ending line
Along the
margin of a bay:
Ten thousand
saw I at a glance,
Tossing their
heads in sprightly dance.
(From: I
Wandered Lonely as a Cloud, Wm. Wordsworth, 1770-1850 )
Noctilucent Clouds
Noctilucent clouds (NLC) are
located in the earth’s Mesosphere at a height of 82km, unlike ‘normal’ clouds
which form in the Troposphere. Their name originates from Latin, meaning, ‘night shining’) and are also known as Polar Mesospheric Clouds.
Little is known about them, and the current consensus among scientists is that
they are composed of meteoritic dust particles encased in ice crystals. Temperatures
in the mesosphere are -100°C, and what little
water is found there immediately freezes around the dust particles, which act
as ‘seeds.’ Through the process of nucleation, the clouds drop to a lower
altitude and are then visible. Exciting and mysterious, NLC are best seen
during the summer months at latitudes north or south between 50° and 65°.
