By the University of Zurich in SciTechDaily –
In the last 25 years, scientists have discovered over 4000 planets beyond the borders of our solar system. From relatively small rock and water worlds to blisteringly hot gas giants, the planets display remarkable and unexpected variety.
The sophisticated computer models, with which scientists study the formation of planets, also spawn very different planets. What the models have more difficulty to explain is the observed mass distribution of the planets discovered around other stars. The majority have fallen into the intermediate mass category – planets with masses of several Earth masses to around that of Neptune.
Even in the context of the solar system, the formation of Uranus and Neptune remains a mystery. Scientists of the Universities of Zurich and Cambridge, associated with the Swiss NCCR PlanetS, have now proposed an alternative explanation backed up by comprehensive simulations.