nine planets are in our solar system.
nine planets are in our solar system.
how many planet are in our solar system?
nine
of the many exoplanets discovered, most have a higher orbital eccentricity than planets in our solar system. exoplanets found with low orbital eccentricity, near circular orbits, are very close to their star and are tidally locked to the star. all eight planets in the solar system have near-circular orbits. the exoplanets discovered show that the solar system, with its unusually low eccentricity, is rare and unique. one theory attributes this low eccentricity to the high number of planets in the solar system; another suggests it arose because of its unique asteroid belts. a few other multiplanetary systems have been found, but none resemble the solar system. the solar system has unique planetesimal systems, which led the planets to have near-circular orbits. solar planetesimal systems include the asteroid belt, hilda family, kuiper belt, hills cloud, and the oort cloud. the exoplanet systems discovered have either no planetesimal systems or one very large one. low eccentricity is needed for habitability, especially advanced life. high multiplicity planet systems are much more likely to have habitable exoplanets. the grand tack hypothesis of the solar system also helps understand its near-circular orbits and other unique features.
orbital eccentricity
bullet::::- hip 11915 (a solar analog whose planetary system contains a jupiter analog)









































bullet::::- lists of geological features of the solar system









































bullet::::- list of gravitationally rounded objects of the solar system









































bullet::::- list of solar system extremes









































bullet::::- planetary mnemonic









































bullet::::- solar system in fiction









































section::::external links.









































bullet::::- dmoz page for solar system









































bullet::::- origin of the solar system (outline)









































bullet::::- a cosmic history of the solar system









































bullet::::- a tediously accurate map of the solar system (web based scroll map scaled to the moon being 1 pixel)









































bullet::::- nasa/jpl solar system main page









































bullet::::- nasa's solar system simulator
outline of the solar system