THE GRAY LAND OF THE MOON.
The rest of the moon is extremely rough, the southern hemisphere in particular presenting the most singular circumambient scenery of thousands of round pits fringed by lofty ramparts of circular mountains.
With the aid of a small telescope, the grayish spots on the moon somewhat resemble seas as they might appear at a great distance. Thus old astronomers, believing that they might at least be ancient sea-bottoms from which the water had evaporated, named them accordingly—although rather romantically. These names are still retained, disguised in Latin on the map of the moon and referred to in Latin by present day astronomers. Translated, however, they add a quaint glamour to the Gray Land and the eye wanders interestedly over "The Sea of Showers," "The Sea of Tranquillity," "The Sea of Clouds," "The Sea of Nectar," "The Gulf of Dews," "The Ocean of Storms," "The Bay of Rainbows," "The Marsh of Sleep" or "The Lake of Dreams."
Since the days of Galileo, improved telescopes and continued research have constantly increased our knowledge of the moon. The curious so-called "seas" are not, seemingly, old sea-bottoms; they are dark plains on the lunar surface much more likely to be great lava plains than sea-basins, according to the evidence that has been collected. Many scientists now regard these areas as a part of the surface where the thin crust became weakened and succumbed in an early stage of the moon's development; the lava then welled forth from the interior and flowed out in great molten sheets over the surrounding country. Since over 100,000 craters have also been observed on this side of the moon, all in fairly good condition, and since there has been no weathering, it is sometimes said that the moon presents a picture of the volcanic age petrified.
The gray patches are best seen when the moon is full. Under a telescope these areas appear darker with occasional traces of yellow or green tints. The colors may be due to some form of vegetation or masses of colored volcanic material.
MOON MOUNTAINS
The most prominent mountains on the moon are the Apennines. These extend in a continuous curve for 450 miles a little north of the center of the moon, forming an impressive "shoreline" for Mare Imbrium, the "Sea of Showers." Running northward, just above the Apennines, is the Caucasus range, and east of the Caucasus, lie the Alps. The Alps and Caucasus mountains are far less conspicuous than the Apennines, for not only do these latter mountains reach into a higher altitude but they also are crowned along their 450 miles with some 3000 steep and rugged peaks.
The Alps are noted for a remarkable flat-bottomed valley which cuts in a straight line through these mountains for a distance of 80 miles. This valley is from to 6 miles wide and at least 11,000 feet in depth. Such a long, level strip bordered by gigantic mountains is as unique a formation as the mammoth craters with the towering rims.