Earth

salt, sulfates, and dust–that come from both natural and human activities. Though they aren’t always visible to the human eye, satellite sensors can reveal global patterns. This image, created using NASA MODIS data highlights the global distribution of the particles.

Larger aerosols (shown in green) tend to have natural sources: Salt aerosols are visible over the oceans, and a dust is visible over the Saharan desert. Finer-grained urban aerosols are concentrated over the eastern United States and eastern Asia, particularly China. The fine aerosols in subtropical Africa are related to agricultural fires.

Image information: This image shows aerosol particle radius during August 2009. For more details, please visit the NASA Earth Observations (NEO) page.Credit: NASA/Goddard Space Flight Center

–Adam Voiland, Goddard Space Flight Center