NEW YORK -- A planet about 400 light years away has a similar density and size to Earth, yet is much hotter and can't support life, two studies found.
Kepler-78b, discovered earlier this year using data from the National Aeronautics and Space Administration's Kepler Space Telescope, is probably made of rock and iron like Earth, according to two studies published Wednesday in the journal Nature. The planet, which orbits a star in 8.5 hours, rather than a sun in a year as Earth does, is the smallest for which the radius and mass are accurately known, the researchers said.
"Every new detection is a piece of a larger puzzle," said Francesco Pepe, an associate astronomy professor at the University of Geneva in Switzerland and one paper's lead author. "All these pieces of [the] puzzle are important to get a global picture of how planets form, live and die."
Researchers from Geneva and the University of Hawaii at Manoa in Honolulu determined the mass of Kepler-78b and then its density. They implied that the planet is made up of iron and rock.