Remote sensing satellites use a wide range of imaging technology to acquire information about our planet. Such images
can be used to measure natural phenomena or the effects of human activities on the environment. For example, sensors may be
specialized to look at infra-red wavelengths or microwave radiation, particularly useful for looking at weather patterns.
The sensors used in the satellites usually detect one or more type of electromagnetic radiation. This is converted to digital data
that is then transmitted to receiver dishes (similar to satellite dishes used for TV). After the data is processed, they are used to
compile the images which can then be analyzed for specific features of interest. In particular, sequential time related images can
reveal a lot of information. For example, a series of images allowed scientists to track the progress and direction of an oil spill
that resulted from a tanker running aground on San Cristobal in 2001.
(Images courtesy of NASA-Johnson Space Center)