Rarity of Planets with Non-Eccentric Orbits

Rarity of Planets with Non-Eccentric Orbits

TNRTB Archive – Retained for reference information

A team of American astronomers has confirmed an important design feature for the solar system. Their research on the upsilon Andromedae planetary system, the best observed extrasolar planetary system, establishes that the gas giant planets in that system got their high-eccentricity orbits through planet-planet scattering (a kind of gravitational slingshot effect). Specifically, at some time in the past upsilon Andromedae had four gas giant planets, rather than the present three. The fourth came too close to the third, kicking it into a highly eccentric orbit which in turn disturbed the orbit of the second. The fourth planet was ejected from the system. The team believes that such planet-planet scattering explains why all extrasolar planets located more distant from their stars than Venus is from the Sun exhibit orbits too eccentric to permit the existence of a life-support planet in the same system. Consequently, the team leader, Frederic Rasio, concluded, “While planetary systems around other stars may be common, the kinds of systems that could support life … may not be so common.” Thus, the circular orbits of the solar system planets appear to point to supernatural design rather than natural outcome.