Asked by: Danielle

The same occurs on the moon. However, the difference is that It takes 28.5 days for the moon to spin about its axis. So one moon-day is 28.5 Earth-days long!

When we watch the phases of the moon we are actually watching the transition of moon-day to moon-night and vice-versa. Because the moon orbits the Earth in exactly the same amount of time it takes for the moon to complete a turn, the same side of the moon is always facing the Earth. (Originally the moon spun faster, but slowed down to reach this curious steady state). So you can pick a place on the moon and watch over a month as it goes from light to dark (this is called 'waning' and corresponds to moon-dusk) and then back again (waxing, which corresponds to moon-dawn) !

Answered by: Sally Riordan, M.A., Management Consultant, London

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'A theory with mathematical beauty is more likely to be correct than an ugly one that fits some experimental data. God is a mathematician of a very high order, and He used very advanced mathematics in constructing the universe.'**Paul Dirac**

(*1902-1984*)