On board the plane that measures pollution
This is one of the most advanced scientific planes in the world - it can fly 10km up into the air, through hurricanes, and even over polar ice caps.
The plane is in charge of measuring pollution levels in the UK's cities.
It's run by the Facility for Airborne Atmospheric Measurements (FAAM), a UK group of scientists and meteorologists.
Watch Martin as he takes a flight over Manchester and Liverpool to see how it all works.