The study of exoplanets, planets beyond the solar system, is a fairly new area of scientific study. One of the primary goals of studying exoplanets is to find a world similar to Earth. And I think that this topic captures the publics imagination and interest like nothing else. No matter who you are we have all wondered about this question: are we alone in the universe?
Since the discovery of the first exoplanet in 1996, scientists have found thousands more. The majority of which are gas giants, many of which have masses higher than Jupiter. It's only been in the past few years that astronomers have begun to discover Earth-like worlds around other stars. The first confirmed planet to orbit in the habitable zone of its parent star was Kepler-22b, discovered in 2011. Kepler-22b, however, belongs to a new class of planet called a super-earth. As the name suggests, these planets are much larger than Earth, although it's still possible that they are habitable. However, there has been some debate about the composition of Kepler-22b. Some scientists believe that it's actually a mini-Neptune rather than a super-earth. Others believe that it's a rocky world covered in a global ocean. It may remain unknown forever which is true.
The discovery of Kepler-22b was only the beginning. More Earth-like worlds have been discovered since then, some of which are much better candidates than Kepler-22b. One such planet, discovered in 2013, was Kepler-62f, a super-earth located in the habitable zone of the star Kepler-62 around 1,200 light years away in the constellation Lyra. Kepler-62f is considered to be one of the best candidates for another Earth. Kepler-62f wasn't the end. More exoplanets were soon discovered which may even be better candidates. ( first comment below 👇👇👇)