For decades, planetary astronomers have postulated the existence of planets orbiting other stars For decades, planetary astronomers have postulated the existence of planets orbiting other stars. Only in the last several years, however, have specific extrasolar planets been inferentially identified by various techniques, primarily from observations of perturbations in the motions of stars. Although there is still disagreement among the scientific experts with respect to the exact nature of the conclusions that can be drawn from this indirect data, it is generally accepted that at least some of the observations do indeed confirm the existence and location of planets outside our solar system. So far, most of the extrasolar planets that have been discovered are very large in size , roughly comparable to Jupiter in our system. The preponderance of large planets that have been identified does not indicate anything about the distribution of planet sizes in other planetary systems.
Larger planets are simply much easier to see using the motion perturbation techniques.
The signature of the vast majority of the smaller planets is still below the threshold of identification with current methods. The discoveries that have been recently made, however, have already catalyzed a revolution in planetary astronomy. Existing models describing the formation and evolution of planetary systems, for example, are currently being reexamined in view of the large number of strange, or oddball, planetary entities that have been found. Based on the extrasolar planets discovered to date, it appears that the range of possible planetary systems is much broader than previously thought. Confirmation of the existence of specific planets outside the solar system represents a major scientific breakthrough.