NASA has announced the first-ever discovery of an Earth-size planet that could hold liquid water and in its star's habitable zone. The announcement was made at a press conference and the findings and details of the research have been published in Science.
The planet, Kepler-186f, was discovered by NASA's Kepler mission. Although scientists don't know the density of the object or its age, they suspect it is rocky with a stronger gravitational pull than we feel on Earth.
The discovery of Kepler-186f confirms that planets the size of Earth exist in the habitable zone of stars other than our sun. While planets have previously been found in the habitable zone, they are all at least 40 percent larger in size than Earth and understanding their makeup is challenging. Kepler-186f is more reminiscent of Earth.
Kepler-186f, which is similar but not exactly the same as Earth is one of 5 planets circling the star Kepler 186, which is smaller than our sun. According to NASA , the next steps in the search for alien life include looking for Earth-size planets orbiting within the habitable zone of a sun-like star(or true Earth-twins) and measuring their chemical compositions.