Whiter regions are objects that are highly reflective. The oceans are usually dark while snow and thick clouds are bright. Don't be fooled by visible imagery. Latest GOES-8 visible image . Latest GOES-9 visible image .
All objects emit electromagnetic radiation.
The infrared radiometers on satellites measure radiation with wavelengths of 11 microns. For easy interpretation, the radiant energy measured by infrared radiometers is converted to a temperature. Cold objects are white and hot surfaces appear black. Time sequences of infrared images are animated and shown on television news stations. Don't be fooled by infrared imagery.