On this week's Naked Scientists, we tackle your questions. We find out what creates a 'Moonbow', how much water there was on Earth over one million years ago and what happens to milk in the freezer. Also, how butterflies could remember what caterpillars learn, why electric cars may stress stretched water supplies and how the 'smell' of a coral reef attracts fish from miles around. Plus, we speak to Marc Abrahams, creator of the Ig Nobel awards for science that makes you laugh, then makes you think! And in Kitchen Science we try to strike a balance between two balloons! Like this podcast? Please help us by supporting the Naked Scientists)