THE SOUTHWORTH PLANETARIUM 207-780-4249 www.usm.maine.edu/planet 70 Falmouth Street Portland, Maine 04103 43.6667° N, 70.2667° W Founded January 1970 "What happens in the Milky Way stays in the Milky Way" THE DAILY ASTRONOMER Thursday, January 28, 2016 Lake of Dreams and Sea of Clouds Imagine if they had been right! By "they," we're referring to the previous astronomers who believed that Venus was a paradise beneath clouds; that Mars was a majestic kingdom replete with chimerical creatures; and that the lunar terrain was dotted by towering peaks and deep oceans. Imagine how the space program might have been vastly different if we were in close proximity to three dynamic, life-bearing worlds as opposed to the inhospitable spheres that surround us. (The hell furnace Venus; the frigid desert world Mars; and the bleak desolation of the Moon.) Perhaps by this time, our more affluent citizens might have been vacationing on some of these exotic worlds. Instead, we've deployed space probes to these planets, and, of course, also sent twelve of our more intrepid citizens to the Moon. As tourist venues, they have little to recommend them. Nevertheless, astronomy types think these outer orbs are all poised on pinnacles, simply by the virtue of their locations beyond Earth's air. We love them for their personalities. One world that remains paramount in our estimation, the Moon, has little to no water. Whatever water it might still retain is locked in frozen storage within a dark southern pole crater. However, when one peruses a Moon map, one cannot help but see curious place names such as Lacus Somniorum, the "Lake of Dreams," or Mare Nubium, "The Sea of Clouds." If Luna is sans H20, how can it contain lakes and seas? It doesn't, but remember that people once thought it did. And, so convinced were they that the Moon was water-logged, the early selenograpehrs, those who mapped the Moon, included seas and lakes in their charts. The 17th century astronomer Langrenus (1598-1675) produced the first lunar map which included the "lakes and oceans." Subsequent maps reproduced their locations and most of their names, ones we still have today. The first lunar visitors, Neil Armstrong and Buzz Aldrin, landed in the "Sea of Tranquility." It was only within the last century that we realized that those "seas" and "lakes" are regions where basaltic lava flows solidifed: leaving wide splotches of dark terrain that resemble oceans when viewed at a distance. Even when we determined the true nature of these regions, didn't change their names, as they had been in use for years and astronomers truly are a sentimental lot. So, the Moon has neither dreamy lakes nor cloudy seas, but instead is a vast, barren sphere devoid of air, water and life. Nevertheless, in our own fanciful reckoning, we still map the Moon as though it were a watery world similar to our own. We don’t allow our contrary knowledge to interfere with our fantasy