NEAR FIRST QUARTER 7 DAYS OLD

moon The Moon, seven days from New, is just a bit shy of first quarter. The terminator, the sunrise line, runs along the left-hand side. North is to the top. The color of the Moon is the result of reddening by the Earth's atmosphere, the nature of the film used, and the actual color of rock. Mare Serenitatis and (lower down) Tranquillitatis dominate the upper part of the picture, with Foecunditatis down and to the right, Crisium up and to the right. The Imbrium basin is just seeing sunlight at far upper left. Numerous craters stand out in strong relief along the terminator, where shadows are long. At the top are prominent Aristoteles and Eudoxus, while near dead center are much larger Hipparchus (on top) and Albategnius. Werner is the middle crater of the trio about 3/4 of the way down. Walter, below it, is just catching the first rays of sunlight. The large crater down and to the right of it is Stoefler. To set the scale, Hipparchus is 150 km (93 miles) in diameter. A bright ray -- splash mark -- from the young southern crater Tycho (still in night) falls across Mare Serenitatis.