Looking for that Next Earth

A lot of attention is being paid to the newly discovered Kepler 10c, a planet twice as large as Earth and 17 times heavier.  About 560 light years from Earth, this planet takes 45 days to orbit its sun.  In the Harvard-Smithsonian Center for Astrophysics press release announcing the finding, researcher Dimitar Sasselov, director of the Harvard Origins of Life Initiatives, stated "This is the Godzilla of Earths!" But unlike the movie monster, Kepler-10c has positive implications for life."

What I find even more interesting is the age of  the solar system hosting Kepler-10.  It is about 11 billion years old, having formed less than 3 billion years after the Big Bang.  So in addition to a planet more than twice the size of Earth, it is also more than twice as old.  What does this rocky world tell us about the available elements for planet building.  And what has been happening on that planet all this time? 

Estimates on the number of Earth-like planets and the likelihood of life continue to abound.  One recent paper, Assessing the Possibility of Biological Complexity on Other Worlds, with an Estimate of the Occurrence of Complex Life in the Milky Way Galaxy, put the estimated number of Earth-like planets about about 100 million in the Milky Way alone.  The paper concludes, "It supports the view that the evolution of complex life on other worlds is rare in frequency but large in absolute number." That provides ample ammunition for many more stories about new worlds.