At the annual meeting of the American Association for the Advancement of Science a few weeks ago, Dr. Alan Boss of the Carnegie Institute of Science speculated there may be as many as 100 billion Earth-like planets in the Milky Way Galaxy.
Boss seems to be extrapolating that numbered based on the distribution of the 300 or so planets in other solar systems discovered so far. The announcement seems time to promote Boss’ book, The Crowded Universe, which makes this argument,
We are nearing a turning point in our quest for life in the universe-we now have the capacity to detect Earth-like planets around other stars. But will we find any? In The Crowded Universe, renowned astronomer Alan Boss argues that based on what we already know about planetary systems, in the coming years we will find abundant Earths, including many that are indisputably alive. Life is not only possible elsewhere in the universe, Boss argues-it is common. Boss describes how our ideas about planetary formation have changed radically in the past decade and brings readers up to date on discoveries of bizarre inhabitants of various solar systems, including our own. America must stay in this new space race, Boss contends, or risk being left out of one of the most profoundly important discoveries of all time: the first confirmed finding of extraterrestrial life.
Fortunately, new technology including the Kepler telescope will help more firmly establish the prevalence of Earth-like planets.