Complex sentence: The orbit of the Earth and other planets within our Solar System is roughly circular, however many exoplanets have been found with eccentric orbits, some of which cause them to spend some of their orbit outside of the zone.
Split into simpler sentences: The orbit of the Earth and other planets within our Solar System is roughly circular. However many exoplanets have been found with eccentric orbits, some of which cause them to spend some of their orbit outside of the zone.