Scientists predict Earth-like planets around most stars
The new research, led by the Australian National University (ANU), made the finding by applying a 200-year-old idea to the thousands of exo-planets discovered by the Kepler space telescope. They found the standard star has about two planets in the so-called Goldilocks zone, the distance from the star where liquid water, crucial for life, can exist.
"The ingredients for life are plentiful, and we now know that habitable environments are plentiful," said Associate Professor Lineweaver, from the ANU Research School of Astronomy and Astrophysics and the Research School of Earth Sciences.
"However, the universe is not teeming with aliens with human-like intelligence that can build radio telescopes and space ships. Otherwise we would have seen or heard from them.
"It could be that there is some other bottleneck for the emergence of life that we haven't worked out yet. Or intelligent civilisations evolve, but then self-destruct."