It is important to realize that knowledge of all the exoplanetary systems we have found so far is constrained by the technology we use to find them. We actually can-not detect the motions of Earth-like planets at all beyond our own solar system, and can only confirm the presence of planets much larger and much more massive. Astronomers are also limited by the amount of time they have been able to search for exoplanets. Jupiter takes more than a decade to orbit the Sun once, so scientists have to observe a distant Sun-like star even longer than that to detect a planet with an orbit like Jupiter’s. As technology improves, it becomes increasingly likely that we will eventually find a planetary system that is very similar to our own solar system.