what can remote sensing satellites tell us about the Earth?

Many things that we here cannot detect. Different spectrum of light of weather helps in interpreting the weather.Seeing seismic cracks in the earths crust . There are many, in infer- red sensing can give very accurate temperatures.

A full answer to this question would take hours to write. Take a look at this Wikipedia article. It will give you a lot of good points and references. http://en.wikipedia.org/wiki/List_of_Earth_observa...