 SPOILER: After Lex Luthor and his gang steal the meteorite at the  museum, a broken glass has the year 1978 written with the  description of the meteorite; which was also the same year the first  Superman came to theaters. Not only did it say 1978, but it had  "Addis Ababa" above the year, which is where Lex Luthor found the  kryptonite meteorite in the original _Superman (1978)_ (qv).