The solar system’s current planetary orbits seem stable, but that’s only because the planets have settled into them over billions of years. The early solar system was a much different place than that seen today, and for almost 20 years, scientists thought they had a good handle on how it got that way. 727 more…
Did a 5th Giant Planet Mess up the Orbits of Jupiter, Saturn, Uranus and Neptune? — Universe Today
Whipped Owl 