Read Futurepundit on this topic. This news increases the expected well-being out there in the universe, but probably lowers the expected welfare of mankind. Visiting aliens could be a boon or a disaster but I am risk-averse in this capacity. Neither my juvenile love for science fiction nor my general optimism make me wish to live to see alien visitation. While earth institutions are far from efficient, they could be much worse. Right now the dominant technological power, the United States, is relatively benevolent by the standards of world history. Technologically superior aliens would upset this balance and could leave too much power in the wrong hands.
This whole news about planets only raises the question anew: Where are they? One possibility is that civilizations simply do not last very long on a cosmic time scale. If intelligent life has evolved elsewhere in the universe, most of the time it has expired before having a chance to contact us. If the window of opportunity is sufficienly small, it would help explain why we do not receive signals from other civilizations.
The research also shows that the nature of Jupiter’s orbit may be responsible for intelligent life on earth:
The simulations show that the amount of water on terrestrial, or Earthlike, planets could be greatly influenced by outer gas giant planets like Jupiter.
“The more eccentric giant planet orbits result in drier terrestrial planets,” Raymond said. “Conversely, more circular giant planet orbits mean wetter terrestrial planets.”
In the case of our solar system, Jupiter’s orbit is slightly elliptical, which could explain why Earth is 80 percent covered by oceans rather than being bone dry or completely covered in water miles deep.
This points to another reason why the aliens have not come. The existence of intelligent life requires a very large number of favorable coincident factors, perhaps larger than we have realized to date. But read Brad DeLong on the Fermi paradox, which suggests a large number of intelligent civilizations out there in the universe, even once we account for all the improbabilities.