NASA has been on the lookout for Earth similar planets for years and the Kepler Space Telescope has been the primary tool for finding them ever since.
Kepler has now monitored more than 150,000 stars that are comparable to our host star, the Sun, in order to find planets that could sustain life and. The telescope has highlighted more than 4,000 candidate exoplanets for further analysis and NASA has, just recently, announced the verification of the thousandth of those worlds.
This development took place after eight more planet candidates were verified by NASA.
The 600 million dollar Kepler Space Telescope was designed specifically to identify exoplanets that are not only real but are also able to support life, meaning that these planets are located within the habitable zones of their host stars where liquid water may exist. Their sizes are also quite similar to Earth and they also have the potential to be rocky.
Well many of the experts would also tell that identifying planets hundreds of thousands of light years away is easier said than done and the error rate is also quite high. And indeed many of the exoplanets are way far for Kepler to see them, but astronomers have developed techniques to measure how a star dims and wobbles when an orbiting planet passes in front of it. This data is then used to estimate size, distance and density of these planets, which further corresponds to this, are these planets terrestrial worlds that could sustain life? So after the verification of Kepler 438-b and Kepler 442-b by NASA, it could be said that these planets should be taken seriously.
Both of these planets orbit smaller and cooler stars when compared to our Sun, which means that their habitable zone lies closer to their host stars.
With these discoveries and verifications, it can also be said that our Earth is not alone and unique and we would be able to find Earth like habitable world in the future.