Landsat satellites offer a unique and crucial view of the world that isn’t available anywhere else. With ERTS-1 in particular, NASA has been able to watch how the world’s been changing on a global scale for the past four decades. This is especially important for observing farmland, as well as grasslands, forests, and other geographical data.
The most recent Landsat satellite was sent into orbit in 1999 and the next is primed to go next year. The Landsat Data Continuity Mission satellite that’s being launched in 2013 will be equipped with the most up-to-date thermal infrared sensors and imaging equipment.
via Slash Gear