The astronaut who wrote his daughter's initials on the Moon

Some dads buy their kids a keychain from a business trip, but an Apollo astronaut permanently vandalized a celestial body. Before leaving the moon in 1972, Gene Cernan drove the lunar rover a short distance away, knelt down, and deliberately traced the letters 'TDC' (his daughter's initials) directly into the dirt. Since the moon has zero wind, those specific letters will outlast human civilization itself.