Apart from proving that TTVs can be used to gauge the mass of transiting exoplanets, the discovery only adds to the fascinating variety of strange new worlds Kepler is uncovering in our galaxy.
"This planet might have the same mass as Earth, but it is certainly not Earth-like," said Kipping. "It proves that there is no clear dividing line between rocky worlds like Earth and fluffier planets like water worlds or gas giants."
Knowing the mass and physical size of KOI-314c, Kipping's team were able to deduce the exoplanet's average density - it is only 30 percent more dense than water. Therefore, the astronomers have deduced, the world must be a rocky world which is covered a dense atmosphere of hydrogen and helium, hundreds of miles thick. It seems likely that the world was once a Neptune-like gas giant, but over time, the close proximity to its star boiled off the vast majority of its atmosphere, shrinking it to a more Earth-like mass.
Kipping and his team presented their findings on Monday at the 223rd meeting of the American Astronomical Society in Washington D.C.