Two Earths in one Solar System

Abstract: The motivation for the project is to investigate what happens if I add a second Earth in the Solar System and project it forward in time. I add an Earth mass planet (called Earth two) in the same orbit as the Earth on the other side of the Sun (i.e. six months ahead of the original Earth). I then investigate how the perturbation of the second Earth effects the Solar System in the short and the long term to see how the interactions between planets occur. These range from the relation between Earth and Earth two, the effect on all terrestrial planets and then on to the whole Solar System. I also consider on what time scales any effects occur. Already in the short term we know that there is no Earth two out there. If it were, it would be in a horseshoe orbit with respect to the Earth and therefore easy to observe. In the long term I find that the system would be unstable. After a number of simulations with small perturbations the vast majority of them end in strong interactions between Venus and either Mercury, Earth or Earth two. The outer planets are practically unaffected by the presence of the extra planet.