# Eccentricity of Exoplanets

The field of astrobiology specifically discovering other planets that revolve around the sun-like star (also known as Exoplanets) has risen since 1990, but certain orbits of exoplanets are observed to have a much wider range in eccentricity than exhibited by the planets in our solar system. What's the reason behind this?

After the gas disc dissipates, the formed planets start to interact dynamically as they do not necessarily form in stable configurations. This can lead to the exchange of angular momentum. A giant planet with small initial eccentricity can hereby pump a lot of eccentricity into less massive planets, as the angular momentum $$L=rmv$$ is conserved.