Binocular Moon Observing Challenge

Although binoculars traditionally have only a modest seven or eight times magnification over the naked eye view, they will bring many lunar features into view. Each of the lunar seas is now seen as an independent body and the brighter craters can now be identified. At crescent phase, the borders of circular Mare Crisium are now evident and shows this lunar sea lies within a great basin that was blasted out of the Moon by an asteroid impact nearly four billion years ago. Binoculars also reveal the bright crater Langrenus near the eastern limb of the Moon. The craters Theophilus and Cyrillus are strategically placed so the shadow contrast of crescent Moon terminator emphasizes their location.

As the Moon phase advances, more of the lunar seas become visible. Three roughly circular lunar seas, Mare Tranquillitatis at the north, Mare Tranquillitatis at center, and Mare Fecunditatis near the limb appear as separate features. Mare Tranquillitatis marks the historic Apollo 11 landing where Neil Armstrong became to first person to set foot on another world. Along the terminator, the Alps, Caucasus, and Apennine mountain chains come into view. These mountains are actually the rim of a gigantic form of crater known as a basin. All of the circular lunar seas lie within a basin. These mountains define the edge of Imbrium Basin that cradles Mare Imbrium, seen from earth as the Man-in-theMoon's left eye.

Near full Moon, binoculars reveal all the classic lunar seas that were named three and a half centuries ago at the dawn of telescopic astronomy. These seas combine to form the friendly face of the “Man-in-the-Moon”. The bright rays systems surrounding half a dozen craters provides a bright contrast to the dark lunar seas.


National Aeronautics and Space Administration