(Translated by https://www.hiragana.jp/)
New Estimate for Alien Earths: 2 Billion in Our Galaxy Alone | Alien Planets, Extraterrestrial Life & Extrasolar Planets | Exoplanets & Kepler Space Telescope | Space.com
The Wayback Machine - https://web.archive.org/web/20130703101746/http://www.space.com/11188-alien-earths-planets-sun-stars.html

New Estimate for Alien Earths: 2 Billion in Our Galaxy Alone

Date: 21 March 2011 Time: 06:37 PM ET