OU Astrophysics Research Suggests New Sequence of Events in Early Solar System
The evolution of the solar system's inner planets during a giant planet instability. Mercury's orbit becomes very eccentric, and the planet eventually hits Venus. Mars is also destabilized toward the end of the simulation.
The conventional model for the solar system's evolutions holds that the giant planets underwent an orbital instability that triggered an intense period of comet and asteroid bombardment 4 billion years ago, the record of which is preserved in the Moon's crater history. However, new research by OU astrophysicist Nathan Kaib and his colleague John Chambers shows that the fragile orbits of the solar system's inner planets are very unlikely to survive a giant planet instability. These new results suggest that either our solar system's architecture is very improbable or that the giant planets become unstable far ealier than previously supposed - before the inner planets had actually formed. This research was covered in the popular journal Forbes.