Torrence Johnson Quotations

Our understanding of the different characteristics of the outer planet moons has undergone a revolution since the Voyager I reconnaissance in 1979. Prior to getting the Voyager data back, most astronomers thought they would find frozen dirt balls with craters on them.

We don't have anything we could call a complete hypothesis yet.

Do you have the right materials and do you the right conditions? The materials are certainly there.

This is a big deal. The south polar region seems to be a geyser field that's bigger than Southern California. . . . We suspect that liquid water also exists on other moons. But none of the water is so close to the surface.

Io is a weird place. We've known that even before Voyager. And each time Galileo has given us a close look, we get more surprises.

These are habitats that are similar to the types of places that we think life could have originated in and possibility still survive in.