i agree with NajaB.. hey.. that rhymes.... <br /><br />The point is, it doesnt have to be tested. Physics says its not possible. to have a translucent/transparent planet. The only way... the only way where an Amosphere can be translucent/transparent is: if the planet had a dense solid core, much like earth, and there was no water/moisture on the planet to make clouds. Earths atmosphere would be transparent if there was no clouds. But if there was no core, there would be no atmosphere because there isnt enough gravity to coalece into a planet. plus our atmoshere is what? 60 miles thick (like looking at the glass of water in my other post)? Thats why gas giants have to be as big as jupiter/neptune/uranus.. they need ALL that mass of ALL that gas to give it the gravity to keep it all together into a planet (like the ocean in my other post). Now, granted, you dont need a planet as big as jupiter. maybe half the size of jupiter, or a little less. But even then, The pressure of all that gas, held together by gravity would give the planet a liquid hydrogen core. Just like propane. Propane is a liquid when its in the tank because the pressure doesnt allow it to evaprate into gas. but when its burned in your bbq, its in a gaseous state. If you had a planet 1/2 jupiter, there still would be too much mass to make it translucent. it would be compressed and dense because of the gravity, and hence when looking at it, and you would be able to SEE the hydrogen. Remember.. there is no such thing as an invisible atom. you put that much of anythign into that much of space, and youll be able to see it. hydrogen and helium are no exception. it would reflect light just as if it where any other planet. but depending on the gas make-up, you might get some exciting looking colors... just look at jupiter saturn, and neptune. preeettyy....