Gathering and recording information from a distance. Space probes have sent back photographs and data about planets as distant as Neptune. In archeology, surface survey techniques provide information without disturbing subsurface deposits.
Satellites such as Landsat have surveyed all the Earth’s surface from orbit. Computer processing of data obtained by their scanning instruments, and the application of so-called false colors (generated by the computer), have made it possible to reveal surface features invisible in ordinary light. This has proved valuable in agriculture, forestry, and urban planning, and has led to the discovery of new deposits of minerals.