Landsat-4
Credit: NASA. Download this image (JPG, 69.8 KB).
Landsat 4 is the fourth satellite of the Landsat program. It was launched in 1982 with the primary goal of providing a global archive of satellite imagery. Landsat 4 carried an updated Multi-Spectral Scanner used on previous Landsat satellites, and a Thematic Mapper (TM). Scientists used TM data to derive the characteristics of tiny particles suspended in our atmosphere, known as aerosols.