Pic Today 11/3/12

PINK CONTRAILS

IN A MORNING SKY

Jet aircraft were painting pink paths

across an early morning sky,

as the sun's first rays cast a

red glow on these thin straight clouds.

For these aren't true clouds,

but "contrails" (a contraction

for "condensation trails.")

It takes a very cold upper atmosphere

to form these exhaust streaks from aircraft,

which are actually water ice crystals from

the combustion of hydrogen rich fuel and oxygen.

Contrails start straight and thin,

but soon broaden and dissipate.

(Brush strokes telling us

winter is on the way.)