Science Buddies: "Ask an Expert"

Hello, today I was playing tennis with my buddies and a little airplane wrote "Jesus Loves U" in the sky right above us, minutes later the phrase was like 500 yards to our left (it moved) and I told them "thats because the earth is rotating" but one of my friends argue that it is because "the wind moved the whole phrase and not because the earth rotates", to me doesn't make sense that the wind blows away the whole phrase but still the wind kept together the whole phrase (not desintegrating the letters), who is right??

have you ever seen clouds move any direction other than east to west? If so, you've probably seen evidence that winds do move clouds.