Everyday skies · human-made cloud
Contrails
Flight paths made visible
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http://www.af.mil/shared/media/photodb/photos/021205-O-9999G-021.jpg
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Full credit
Own work
Displayed at reduced resolution. See the original file for full licensing information.
Full credit
Own work
Displayed at reduced resolution. See the original file for full licensing information.
Swipe or scroll sideways to explore the photographs. Photos may include other cloud types; names and credits come from their source records.
Spot it
Narrow trails behind aircraft that may fade or spread into streaks.
How it forms
Water from aircraft exhaust condenses and freezes in sufficiently cold air.
Read the sky
Persistence reflects conditions aloft, not a direct forecast at ground level.
Where to look
Look along flight routes in cold upper air.
Little sky facts
Reveal fact 1
Contrail is short for condensation trail.
Reveal fact 2
Persistent exhaust trails contain ice crystals.
Reveal fact 3
Dry surrounding air can make a trail disappear quickly.
Reveal fact 4
Humid conditions can let a trail spread and last.
Try this
Turn intersecting trails into a geometric drawing.
Draw your own cloud ↗Read a little deeper
Conditions described here are places to look, not a global frequency ranking. Use local weather forecasts and warnings for decisions. Never look directly at the Sun.