Formation and evolution of the Solar System owe its substantially lower mass simply to having formed a few million years after Jupiter, when there was less gas available to consume. T Tauri stars like the young Sun have far stronger stellar winds than more stable, older stars. Uranus and Neptune are thought to have formed after Jupiter and Saturn did, when the strong solar wind had blown away much of the disc material. As a result, those planets accumulated little hydrogen and helium—not more than each. Uranus and Neptune are sometimes referred to as failed cores. The main problem with formation theories for these planets is the
HD 65216 b of Mars from the Sun, but at periastron the planet is a fifth closer to the star than Earth from the Sun and at apoastron it is over twice as far. HD 65216 b HD 65216 b is an extrasolar planet located approximately 116 light-years away in the constellation of Carina, orbiting the star HD 65216. This planet was discovered by the Geneva Extrasolar Planet Search Team in 2003. Like most planet candidates so far, it was detected with the radial velocity method. The planet has a minimum mass about 20% more than Jupiter. Since the discovery method gives only