K2-18b, which is eight times the mass of Earth, is now the only planet orbiting a star outside the Solar System, or 'exoplanet', known to have both water and temperatures that could support life.
K2-18b, which is eight times the mass of Earth, is now the only planet orbiting a star outside the Solar System, or 'exoplanet', known to have both water and temperatures that could support life.