Jumping-Jupiter scenario Jumping-Jupiter scenario The jumping-Jupiter scenario specifies an evolution of giant-planet migration described by the Nice model, in which an ice giant (Uranus, Neptune, or an additional Neptune-mass planet) is scattered inward by Saturn and outward by Jupiter, causing the step-wise separation of their orbits. The jumping-Jupiter scenario was proposed by Ramon Brasser, Alessandro Morbidelli, Rodney Gomes, Kleomenis Tsiganis, and Harold Levison after their studies revealed that the smooth divergent migration of Jupiter and Saturn resulted in an inner Solar System significantly different from the current Solar System. The sweeping of secular resonances through the inner Solar System during the migration
Hydrus 10180, which has seven planets, plus possibly an additional two for a total of nine—as of 2012 more than any other system to date, including the Solar System. Lying around from the Earth, it has an apparent magnitude of 7.33. GJ 3021 is a solar twin—a star very like our own Sun—around 57 light-years distant with a spectral type G8V and magnitude of 6.7. It has a Jovian planet companion (GJ 3021 b). Orbiting about 0.5 AU from its sun, it has a minimum mass 3.37 times that of Jupiter and a period of around 133 days. The system is