The Family Tree of Exoplanets Has Just Divided Into Two Branches
Scientists have reorganized the exoplanetary tree of life into two distinct branches. Most exoplanets discovered so far are close in size to Earth or either Neptune, according to a new study led by the California Institute of Technology. But astronomers are puzzled as to why there is a gap between these two planetary sizes.
The work, which is based on an analysis of thousands of known exoplanets, shows that planets in our galaxy overwhelmingly fall into two groups.
One explanation could be that many planets are naturally Earth-sized and remain at their original size, while other ones — for reasons that are still poorly understood — acquire a lot of gassy mas.