Extreme weather events are increasing in frequency and intensity and the dynamics of Earth’s atmosphere is ever-changing. A new pan-Canadian collaboration will measure aerosols, water vapour and clouds and how they interact to impact Earth’s weather and climate as part of NASA’s Atmosphere Observing System (AOS) mission. The Canadian Space Agency (CSA) will collaborate with NASA on AOS with its High-altitude Aerosols, Water vapour and Clouds (HAWC) mission. The mission consists of two Canadian instruments on a Canadian satellite and a third instrument on a NASA satellite, all planned for launch in 2031. These innovative instruments will provide critical measurements, enabling Canadian climate scientists and weather forecasters to better understand and predict extreme events like severe storms, floods, droughts and poor air quality conditions.