DEFINITION a atmoshere is a gaseous envelope    surrounding the earth the air. the atmoshere has 5 layer exoshere,      theroshere, mesohere, stratshere and troposhere. the exoshere is  the outer layer and satllites orbit this layer. the theroshere is the the  second outer layer.the temperature drops in this layer.the middle  layer is the stratoshere.it has a protective ozone.last but not least the  troposhere it is the closest layer to earth.