posted on Oct, 6 2011 @ 03:35 AM
A NASA spacecraft has found an unusual three-planet system that consists of one super-Earth and two Neptune-size worlds orbiting a star similar to our
sun, a new study reveals.
The planet-hunting Kepler Space Telescope discovered the three planets around the star Kepler-18, which is only 10 percent larger than the sun and
contains 97 percent of the sun's mass, researchers from the University of Texas at Austin said. The alien system could also host more planets than
have been found so far, they added.
All three planets, which are designated Kepler-18b, c, and d, orbit much closer to their parent star than Mercury does to the sun. The planet
Kepler-18b orbits closest to the star, taking 3.5 days to complete its journey. The planet is about 6.9 times the mass of Earth and is twice the size
of our home planet, making planet b a so-called super-Earth, the researchers said.