Photo 1:
- "Exposing aerial crimes and aerosol operations" chemtrails chemtrail site ;
- "A contrail will form if, as the exhaust gases cool and mix with surrounding air, the humidity becomes high enough (or, equivalently, the air temperature becomes low enough) for liquid water to condense on particles and form liquid droplets." Air Force
Photo 2:
- "NASA scientists have found that cirrus clouds, formed by contrails from aircraft engine exhaust, are capable of increasing average surface temperatures enough to account for a warming trend in the United States that occurred between 1975 and 1994." (global dimming)"NASA
- "NASA image shows intricate web of chemtrails over the US" [http://www.infowars.com/print/misc/gossamer.htm Alex Jones]
- "your life as a human test subject" chemtrails site
- "Shocking NASA Photo & Admission of Chemtrail Cover" rense
- "NASA" chemtrails site-photo submitted by a German chemtrails site
Photo 3:
- "Contrail Pictures from Surface" NASA
- "Your Govt. would kill you, maybe it’s time you take a similar stance relative to them." conspiracies open submission blog
Photo 4:
- "Awesome surface-based contrails photo taken from I-95 in northern Virginia" NASA, photo
- "All normal business plane ?" chemtrails site-photo submitted by a German chemtrails site