Ключевые слова: abstract, air, airplane, airplanes, airspace, background, blue, chemical, chemtrail, chemtrails, clear, cloud, clouds, concept, condensation, contrail, contrails, daylight, environment, fly, high, holidays, jet, jet streams, journey, lines, long, moon, nature, plane, planes, pollution, sky, soft, space, speed, streams, trace, track, trail, trails, transport, transportation, travel, tree, vacation, vapor, weather, white, wind,