Study suggests Io's volcanoes have been active for 4.5 billion years

A team of geologists and planetary scientists from the California Institute of Technology, the University of California Santa Cruz, New York University, and NASA Goddard Space Flight Center reports evidence that Io's volcanic activity has been ongoing since the beginning of the solar system. In their study, published in the journal Science, the group studied sulfur isotopes in Io's atmosphere to determine how long the moon has been volcanically active.