Sunday, 6 June 2010
The next time you see the full moon high in the south, look carefully at its right hand edge and let your eye travel upward along the curve of the disk. Round about two o'clock you will notice a small, dark oval: anyone with normal eyesight can find it quite easily. It is the great walled plain, one of the finest on the Moon, known as the Mare Crisium - the Sea of Crises.
Arthur C Clarke