In KSP, I can do science "from space just above Kerbin's Deserts" or "while flying over Kerbin's Water".
At what altitude do I stop "flying over" and start sciencing "from space just above"? At what altitude am I "in space near Kerbin"? In other words, how low do I have to be for the biome to register?
Moreover, for the Mun (or other biome-bearing body), how close do I need to get in order to register as in "space just above" or "flying over" the Mun's highlands, for example?