Ten Billion Earths ?
Astronomy Picture of the Day, NASA, January 12, 2013,
http://apod.nasa.gov/apod/astropix.html
Announcing 461 New Kepler Planet Candidates, NASA
Kepler News, January 7, 2012,
http://kepler.nasa.gov/news/nasakeplernews/index.cfm?FuseAction=ShowNews&NewsID=244
At Least One in Six Stars Has an Earth-sized Planet,
Harvard-Smithsonian Center for Astrophysics, Jan. 7, 2012,
http://www.cfa.harvard.edu/news/2013/pr201301.html
Best wishes,
Paul H.
