Landsat

In 1972, the United States launched the first of a group of unmanned satellites collectively known as Landsat.

Landsat satellites carry sensors that record “light,” or portions of the electromagnetic spectrum, as it reflects off the Earth.

Landsat acquires digital data that are converted into an image.

Rocks containing limonite, a hydrous iron oxide, may be identified readily from Landsat Multispectral Scanner data.