Transcription: Well, we don't really know yet. That's one of the great exciting questions coming up and I hope in the next several decades we'll have some real answers. I think there are because I don't think it's likely that the Earth was created as the only planet about a star. I think that stars must have produced planets fairly commonly. But until we actually find one and observe it and determine that it's really like a planet on this solar system is still going to be one of those big important scientific questions.
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