VisibleEarth.NASA.gov displays a collection of images and animations of the Earth that users can freely access and download in different formats and resolutions. The license of the images permits users to re-use and re-publish them, but requires them to credit to the National Aeronautics and Space Administration, or NASA.
The images in the Visible Earth project collection are classified both by the sensor that obtained the image and by its topic. The Global Change Master Directory covers topics within the Earth and environmental sciences, such as Atmosphere, Biosphere and Human Dimensions. The Visible Earth website is part of a project called NASA's Earth Observing System.