An international team of astronomers has just discovered a very Earth-like planet orbiting a red dwarf star about 200 light-years from us. According to scientific calculations, it has a weight very similar to that of the Earth but its diameter is 60% larger , which indicates that it must have a very thick gaseous atmosphere.
” This planet could have the same mass as Earth, but it is certainly not Earth-like, ” explains David Kipping, a researcher at the Harvard-Smithsonian Center for Astrophysics (USA) and lead author of the discovery. In fact, taking into account that it takes about 23 days to orbit its star and that its temperature exceeds 100 ° C, the research team doubts that life as we know it exists.
Koi-314c, as this planet has been christened, is only 30% denser than water, suggesting that it is enveloped by an atmosphere hundreds of kilometers thick made up primarily of hydrogen and helium. Thanks to the data obtained by the Kepler telescope, the researchers think that in the beginning this planet could be a kind of small Neptune, and that little by little it was losing gases from its atmosphere due to the high temperatures it must endure.
To measure the weight and size of Koi-314c, the researchers used a non-conventional system. Instead of the usual techniques they used a method known as TTV (transit timing variations ) whose main problem is that it can only be applied when more than one planet is known orbiting the same star. In fact it is a very new technique, used for the first time successfully in 2010 and which, in the words of Kipping himself, “we are leading to maturity”.
