Scientists believe that some other planets in the universe might have a geologic structure similar t0 Earth's, including a mantle and an outer layer made of plates Imagine that scientists have found a planet with an outer layer divided into plates made of hard, solid rock, but the mantle below the plates is made of hard; solid rock instead of soft; solid rock as it is on Earth) Do you think plate motion would take place on that planer? use Bank words to plate plate boundary mantle outer layer