Five planets transiting a larger primary star about 117 light years from Earth may constitute the oldest known system of terrestrial-sized planets, scientists say. The discovery hints at the possibility of ancient life elsewhere in our galaxy, researchers said.
Dr Tiago Campante, an Asteroseismology Research Fellow at the University of Birmingham (UK) who led the research team, focused on a system of five terrestrial-sized planets observed by the Kepler space telescope transiting the star KOI-3158, about 117 light years from Earth in the constellation lyra.
KOI-3158 is the closest and brightest multi-planet system detected so far by Kepler, said Campante. The star system is estimated to be 11.2 billion years old, give or take 900 million years or so “which makes KOI-3158 the oldest known system of terrestrial-size planets,” Campante told a symposium in France earlier this year.
In contrast, our own Sun and solar system is believed to be less than 5 billion years old. The planets circling KOI-3158 are also familiar in terms of their size, with the innermost being about the size of Mercury, followed by three Mars-sized intermediate planets and a fifth and largest planet that is bigger than the other four, but a bit smaller than Venus.