NASA released a Kepler Telescope survey catalogue where 219 planet candidates were listed. The planets were discovered by Kepler outside the Solar System and 10 of them are considered Earth-like and near-Earth-size and are found within the habitable zone.

Out of the new 219 planet candidates, 10 of them stood out. It is because they are almost near-Earth in terms of size. They also orbit their star within the habitable zone. The habitable zone is a distance where the planet orbits its star far enough to receive the right amount of sunlight to enable liquid water to remain on the surface of a rocky planet.

Based on Kepler's mission survey, 10 of the new planets are in the habitable zone. This means, there is water on these 10 planets and in turn, life may thrive or could be thriving in them, too. The discovery of the 10 planets plays a vital role in the search for life outside the Earth.

"This is the most comprehensive and detailed catalog release of candidate exoplanets, which are planets outside our solar system, from Kepler's first four years of data," a NASA official said in a press release. "It's also the final catalog from the spacecraft's view of the patch of sky in the Cygnus constellation."

In total, there are 4,034 planet candidates identified by Kepler telescope where 2,335 were already verified as exoplanets. All in all, there is about 50 near-Earth-size planet candidates in the habitable zone identified by the NASA Kepler telescope and 30 of them have been verified.

The discovery of 10 Earth-like and near-Earth-size planets in the habitable zone also increased the desire of man to question the existence of life outside the Earth. Having flowing water on the surface of a planet orbiting in a habitable zone is indeed a viable condition for life to exist. But since these new planets are outside the Solar System, it may be a long time before the data could be verified.

"Are we alone? Maybe Kepler, today, has told us indirectly, although we need confirmation, that we are probably not alone," Kepler scientist Mario Perez said in a press conference.