New estimate suggests that 18% of Sun-like (G-type) stars could have a planet the size of Earth orbiting in their conservative habitable zone. There may be as many as one potentially habitable Earth-sized exoplanet for every five Sun-like stars in the Milky Way. Image credit: Sci-News.com. Determining the abundance of Earth-size planets in the habitable zones of their stars, where liquid water could exist on a rocky planet’s surface, is one of the...