If you have ever looked up at the sky right after a plane has flown overhead then you will almost certainly have seen the contrails they leave in their wake.
(Contrails are the white plumes of cloud which follow a plane, as seen in the picture below)
Sometimes these contrails seem to linger for a long time, leading some people to suggest that they are not normal contrails at all.
Contrails are actually ice particles that are formed from condensing engine exhaust when a plane flies above an altitude of around 33,000 feet.
These contrails then disappear very quickly.
Chemtrail believers, however, point to trails that linger, expanding over time and which form patterns such as grids or parallel lines, as evidence of something else entirely.
Essentially, they believe that Chemtrails are a form of biological warfare.
More on this over the next couple of days…
Read the rest of the series on Chemtrails and Contrails –