 confirmation of extensive volcanic activity on Io — which is 100 times greater than that found on Earth ; the heat and frequency of eruptions are reminiscent of early Earth ; 
 confirmation of extensive volcanic activity on Io — which <a href='drop_aux' title='1'><mark>is</mark></a>100 times greater than that found on Earth ; the heat and frequency of eruptions <a href='drop_aux' title='2'><mark>are</mark></a>reminiscent of early Earth ; 
Confirmation of extensive volcanic activity on Io — which 100 times greater than dat found on Earth ; the heat and frequency of eruptions reminiscent of early Earth ;