What do air pollution, thunder clouds and climate change have in common? Aerosols! These tiny particles, generated by everything from desert dust storms to car exhaust, play a huge role in our atmosphere, affecting our health when we breathe them in and even changing the weather. Globally, they play an even bigger role, changing how much sunlight gets through to Earth’s surface and heating or cooling our entire planet. Through new satellite missions, NASA atmospheric scientists like Kirk Knobelspiesse and public health experts like Susan Annenberg are working together to untangle aerosol mysteries.