A SERIES OF circular aircraft condensation trails drifts over the Olympic Mountains south of Port Angeles on Thursday. Originally, the trails were thought to be the result of a test flight of a Boeing ...

In cold, damp conditions, soot particles emitted by aircraft cause the formation of ice crystals and condensation trails. Anthropogenic contrail cirrus clouds have an impact on the global climate.

This photograph was taken on 22 June this year in north Pembrokeshire, UK. There were aircraft trails in the sky – but all of them were absolutely straight. So what is this? • That is undoubtedly an ...

Around 100,000 commercial flights criss-cross the skies overhead every day, leaving white condensation trails streaking across the sky. While scientists have studied the impact these increasingly ...