A NASA-funded network of 10 air-quality monitors has given researchers one of the most detailed long-term looks yet at pollution in Addis Ababa.The sensors collected data from 2022 through 2025, tracking PM2.5, tiny particles that can travel deep into the lungs, along with black carbon from fires, diesel vehicles, and other combustion sources.The measurements showed that pollution changed by time of day and season. They also helped researchers distinguish particles from holiday bonfires from particles produced by fossil-fuel combustion.The new record gives Addis Ababa a baseline for understanding how air quality changes as the city grows. NASA says the findings may help researchers in cities around the world study and manage air pollution more effectively.