A small mineral tidbit in a rock brought back from the moon in 1972 is giving scientists a big clue that our satellite’s surface was, for the most part, solidified by 4.4 billion years ago.
A small mineral tidbit in a rock brought back from the moon in 1972 is giving scientists a big clue that our satellite’s surface was, for the most part, solidified by 4.4 billion years ago.