Planet like Earth are moving around at least one star among every six stars in the galaxy. According to this, the total number of Earth-sized planets in the galaxy are 17 billion as said by astronomers. BBC said that astronomers has analyzed the data obtaining from Kepler telescope of NASA which is the space research institute of USA. Their study found that planet, around one and half times of earth, are moving 17% of stars. Their annual pace is 85 days or more which is like the smallest planet in the solar system, Mercury. As to this there are at least one thousand seven hundred billion planets in the galaxy.
