There have been many findings of Earth like planets, but none have been exactly the same. The search for our twin is still underway as astronomers are hoping to find another Earth that has the same composition and density as our planet.
Kepler-186f is the first validated earth sized planet in the habitable zone of its star. This planet orbits its star every 130 days, which places it in the habitable zone, although our earth does a full rotation around the sun every 365 days, we must take into consideration the size of Kepler-186 sun which is considerably a lot smaller. Kepler 186f resides in the Kepler 186 system, which is about 500 light years from earth in the Constellation Cygnus. A constellation is a group of stars which form a pattern that is recognizable that is typically named after the apparent form of a mythological creature.
Scientists believe that this planet is most likely to be a rocky world, but are unable to determine the mass and density. As Kepler 186f is not identical to Earth which revolves around a bigger and brighter star, it revolves around a red dwarf star. This planet is not a true Earth twin but rather a cousin.
Kepler-452b the most recent and probably the closest twin Earth-like planet has been found with the use of the Kepler telescope. This planet is 1,400 light years away and orbits its star in 385 days, which is just 20 days longer than our own year. Its star is just 4% larger and a billion and a half years older and 20% brighter than the sun which clearly indicates that the 452b resides in the habitable zone. The odds of this planet being rocky and with liquid water is higher than any other planet that has been found with the use of Kepler.
There have been other planets that have a potential to be like Earth however their stars aren’t as comparable to a G Star which currently Earth is rotating around.
Technology is rapidly evolving, within the distant future we as human beings could possibly be reaching these planets that are light years away. This however will certainly not be in my life time but will definitely be in the future.
NASA has been planning for more exoplanet missions that will be launching in the next few years. Typically these are successors of the Kepler and Hubble telescopes but also, new technological advances to find our twin Earth.