%0 Journal Article %T Exponential law as a more compatible model to describe orbits of planetary systems %A K Naficy %A A Ayubinia %A M Saeedi %J Iranian Journal of Physics Research %D 2012 %I Isfahan University of Technology %X According to the Titus-Bode law, orbits of planets in the solar system obey a geometric progression. Many investigations have been launched to improve this law. In this paper, we apply square and exponential models to planets of solar system, moons of planets, and some extra solar systems, and compare them with each other. %K exponential and square models %K planetary orbits %K extra solar planets %U http://ijpr.iut.ac.ir/browse.php?a_code=A-10-1-591&slc_lang=en&sid=1