A newly discovered planet called Kepler-186f, about the same size as Earth, appears just right for us to live life as we know it, according to an international group of astronomers. However, NASA deems it as more of a cousin, rather than a twin.

Orbiting a star about 500 light-years away, Kepler-186f orbits its star at the right distance for liquid water on the surface, which is an essential condition for life as we know it, Voice of America reported.

But it cannot be determined to be exactly like Earth, NASA planetary scientist Elisa Quintana said via Skype. "It's more of an Earth's cousin. It's not an Earth's twin. It shares the same characteristics as Earth, but their parent stars are very different," said Quintana, adding that Kepler-186f orbits a star that is smaller and cooler than our sun.

However, the planet still appears to be a closer relative than most of the hundreds of others discovered so far, including massive gas-covered giants with thick, crushing atmospheres and planets that orbit too closely to their stars and are too hot for life, astronomers said in the journal Science.

Although two planets discovered last year are in the right orbit and might be good candidates for life, Quintana said, they are a bit bigger than Earth. "For the first time, we can actually say we now have a planet that is both Earth-sized and orbits in its star's habitable zone," she said.

In the meantime, a more sophisticated space telescope would be required to take the next step and search for traces of life in the atmospheres of these distant worlds. But the mission is being threatened by budget cuts, said University of California at Los Angeles astrophysicist Ben in a Skype interview to VOA.

"In principle, we could do this in the next couple decades.  But in practice, because there's no money, it's not gonna happen. It's not gonna happen in my lifetime, for example," said Zuckerman.

Leaving earthbound concerns behind, NASA's Elisa Quintana believes that when the next-generation space telescope is launched, it will find that we are not alone in the universe, according to VOA.

"I guess I'm an optimist. I think that life is definitely out there. Just looking at the abundance of stars. I mean, hundreds of billions of stars. The likelihood that one of them might have some form of life to me seems rather high. But everyone has their own opinion about that, I'm sure," she said.