Luna is a planetoid that is considered to be a moon of the planet Earth. For much of Human history, Luna was referred to simply as "the Moon". This largely ceased in the era of interstellar travel, though many natives still use the archaic name. In Earth slang people who lived on the moon are called "Lunar schooners." By 2155, Luna was the location of a great many mining facilities. By 2578, Luna was inhabited by over 50 million people, with such colonies as New Berlin, Tycho City, and Lake Armstrong found on its pressurized surface.