Cosmic curveball: Distant system challenges planet-formation theory‎

An international team of astronomers has discovered a distant planetary system that challenges long-standing theories of how planets form. Across our galaxy, astronomers routinely observe a characteristic pattern in planetary systems: rocky planets orbiting close to their host star with gas giants farther away. Our own solar system follows this rule, with the inner planets: Mercury, Venus, Earth and Mars, composed of rock and iron, and the outer planets: Jupiter, Saturn, Uranus and Neptune being predominantly gaseous.