Planetary Systems: from Plutos to Jupiters

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Our solar system contains a healthy ecosystem of bodies, including a multitude of dwarf planets (like Pluto), a handful of Earth-like solid planets, and a similar number of giant planets. It is natural to wonder about the origin of all these planets. Over the past two decades, the number of planets that we can study have increased from a mere 8 to thousands. The observations of extra-solar debris disks also disclose the presence of dwarf planets around other stars. A new framework for planet formation is called for, to explain the astounding diversity as well as the emergent universality observed in these systems. We propose a theoretical research program to answer the following questions: How do a planetary system, emerging out of the gaseous disk that disappears after a few million years, manage to maintain their stability billions of years? What organize them into their observed peaceful coexistence? Orbits of our terrestial planets are chaotic, but, fortunately, with a stability lifetime comparable to the solar system lifetime. Who orders that? Is this also true for other planetary systems? Do majority of planetary systems look at all like our solar system? We will also study the Kuiper belt region to address these questions: How do Pluto and other Kuiper belt objects form in our solar system? Many stars have debris disks orders of of magnitude brighter than our own Kuiper belt. Why is ours so anemic? Are solid materials in these bright disks forming into Earth-like or even Neptune-like planets? Or is planet formation in these regions stalled by stirring by sibling giant planets? Answers to these questions provide us with important pieces to unravel the great mystery of how planets arise. Our study is a part of the human endeavour of trying to find our place in the cosmos.