[Timeline showing lifespans of the Landsat satellites. Credit: NASA]
The Landsat mission began 40 years ago with the launch of Landsat 1 in 1972. The key objective was to study and monitor our planet’s land masses but with the advancement in science the range of potential uses of Landsat imagery expanded dramatically to cover many disparate disciplines, including study of climate, carbon cycle, ecosystems, water cycle, biogeochemistry, changes to Earth’s surface, effects of human activities on land surfaces, and much, much more.
Landsat 8 will orbit the Earth every 99 minutes and will be able to image Earth every 16 days. It carries two new sophisticated instruments, Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). These two sensors will provide seasonal coverage of the global landmass at a spatial resolution of 30 meters (visible, NIR, SWIR); 100 meters (thermal); and 15 meters (panchromatic). The OLI provides two new spectral bands, one tailored especially for detecting cirrus clouds and the other for coastal zone observations, and the TIRS will collect data for two more narrow spectral bands in the thermal region formerly covered by one wide spectral band on Landsats 4–7. The satellite is programmed to return 400 scenes per day (150 more than Landsat 7), increasing the probability of capturing cloud-free scenes.
All Landsat 8 data is free and will be available for download via Earth Explorer.