Planets, Planets a[euro][umlaut]Everywhere
Kaku, Michio, Newsweek
Byline: Michio Kaku
And 17 billion are the size of Earth.
tonight, after reading this article, you will never see the starry night sky in the same way again. Gazing at the splendor of the Milky Way galaxy, you will ask yourself, "Is anyone looking back?"
It's official: in our own celestial backyard, our galaxy holds 100 billion planets, a number beyond human comprehension. About half the stars in our galaxy have planets going around them; however, most of them are huge and unable to support life as we know it. But many--about 17 billion--are roughly the size of Earth. For the first time in his tory, we now have a "census" of the galaxy extrapolating from a sample: about one in six stars has Earth-size planets revolving around them.
These are the astounding results from the Kepler satellite, announced this week at the American Astronomical Society Meeting in Long Beach, Calif. The Kepler satellite, launched in 2009, can detect tiny Earth-like planets because they occasionally pass in front of their mother star, causing a slight dimming of starlight. Kepler has now identified 2,740 potential planets orbiting 2,036 stars, in this way.
This raises the eternal question: is anyone out there? Back in 1600, the former monk Giordano Bruno was burned alive in the streets of Rome for claiming that life can thrive on alien planets. Fortunately, we don't burn astronomers at the stake anymore. But it does raise interesting theological and philosophical questions about our place in the universe. Arthur C. Clarke once said, "Either intelligent life exists in space or it doesn't. …