Satellite images from NASA and the European Space Agency show pollution over China is down since the novel coronavirus outbreak.
Gases are hardly visible in the pictures from February 10-25.
The earliest signs of change were over Wuhan, China where COVID-19 was first detected in December 2019.
RELATED: Everything Americans need to know about coronavirus
The virus has since spread globally, killing thousands and infecting tens of thousands more. The pandemic has affected the economy, travel and politics.
To learn more about the coronavirus go to the Centers for Disease Control and Prevention.