After pressing some buttons to start up the ascent engine of their lunar module Challenger, astronauts Gene Cernan and Harrison Schmitt left the Moon on December 14, 1972. That’s 39 years ago – before many of us were even born. While these men looked out the tiny triangular windows of the lunar module to see the lunar surface getting farther away, viewers around the world watched that same spacecraft leave the Moon, live and in color on their television sets.