Habitable planets may be hundreds of one billion.

<P Align=center> </ P> <P align=center> the star Gliese 436 scientists drawn renderings </ P> World Scientific reports [tech.] News: Comprehensive media reports, 28 U.S. astronomers said, the Earth lies .not unique in the solar system, habitable planets may be billions of dollars. .<P Align=left> researchers 28 in Honolulu at the American Astronomical Society (AAS) meeting, said that the recent discovery of extrasolar planets have been made (exoplanet) increased to 236 the number. .The leader of the study, the University of California, Berkeley professor of astronomy Marcy (Geoffrey Marcy) that the Earth is not rare in the universe of planets. .</ P> <P align=left> he said, "We can easily see running around other stars, like Jupiter and Saturn, as the giant planets. Like our Jupiter and Saturn, the majority of these planets are orbiting the distance .stars very far in the planetary system which is very common structure. "but the researchers noted that, while not a new technology allows astronomers discovered giant planets, like Earth-sized planets still can not be observed. .</ P> <P align=left> they found four classes with multiple planets solar system, the most exciting of which was 3 years ago found a planet. .Planets like Neptune Fengyun star Gliese 436 is running around, the surface seems covered with water, thus causing the interest of scientists. .</ P> <P align=left> Marcy said, "It's a density of 2 kg per cubic centimeter, is twice as much water, so it must be half by the rocks, about half of the water composition, and perhaps a small amount of .hydrogen and helium, and now we think it has a rocky core, covered with a layer of water. "He also said that scientists proposed the theory of decades ago, but conclusive evidence has begun to emerge. .He believed that the Milky Way has 200 billion stars. .Perhaps the composition of the galaxy is estimated that billions of planets in a habitable. .</ P> </ p>.