2012 Spring Semester Topics in Current Astronomy - Formation and Evolution of Planetary Systems - Course ID: Building 19 / Room number 207 for Graduate Students Instructor: M. Ishiguro

Purpose of this Lecture (1) The major purpose of this course is to understand the physical properties and diversity of planetary systems. We have long speculated about the possibility of life outside of the Earth. We seek for the generality of Earth-like planets and the life in the universe, and consider the place of human beings in the universe. Thanks to the advanced technologies, a wide range of planetary systems has been discovered, with a variety of different size and orbital properties around different types of stars. On the other hand, sophisticated numerical integration of Solar System objects enables to study the past catastrophe. Space explorations allow us to investigate the compositional studies of Solar System primitive materials.

Purpose of this Lecture (2) On the basis of these recent findings, I will first review the knowledge of formation, physical and chemical evolution of Solar System, and connect the knowledge to the extrasolar planetary systems. Later, YOU are supposed to introduce one chapter in the textbook, “Planetary Systems”. I will support your individual initiatives. I welcome your active participation in the class. I will give consideration to those who do not major in planetary science and the related field.

References Planetary Systems, M. Olivier, et al. 2009, Springer Physics and Chemistry of the Solar System, J. S. Lewis, Elsevier Academic Press Comets and the Origin and Evolution of Life, P. J. Thomas, et al., Springer Solar System Dynamics, C.D. Murray & S.F. Dermott, Cambridge University Press

Evaluation

Tentative Schedule

Current Solar System (1) Planets and Dwarf Planets

Distribution of Current Solar System Main-belt Trans-Neptunian-object Terrestrial planets Gas giant planets

Oort cloud is a hypothetical spherical cloud. No direct observations AU; defines gravitational boundary of solar system Source of long-period Comets (note) Nearest Star (alpha Centuri) at 4.2 light year = 1.3 pc = 2.6x10 5 AU

Terrestrial (or inner rocky) planets: Mercury, Venus, Earth, and Mars Asteroid belt: Rocky objects. Some asteroids around the outer edge may have ice deep inside the bodies (?). Gas Giant Planets: Jupiter, Saturn, Uranus, and Neptune Trans-Neptunian Objects – Pluto is no longer defined as a planet. – Edgeworth-Kuiper Belt Objects: Icy bodies, located beyond the planets extending from the orbit of Neptune (at 30 AU) to approximately 55 AU from the Sun – Scattered Disk: Icy bodies: These objects have eccentric orbits, and perihelia greater than 30 AU. (e.g. Sedna) – Oort cloud: nearly spherical swarm of comets, originally formed in outer solar system.

Main-belt TNOs NEO Comets

DiameterMass Semi-major axis Rotational period Number of satellite Ring Atmosp here Terrestrial planets Mercury no No substantial Venus noCO 2, N 2 Earth11111noN 2, O 2 Mars noCO 2, N 2 Gas planets Jupiter >63yesH 2, He Saturn >60yesH 2, He Neptune yesH 2, He Uranus yesH 2, He Dwarf planets Ceres no- Pluto no No substantial

Sun begins fusion. Strong winds clear away nebula. Remaining planetesimals near planets get swept up or flung out. There is a slowly rotating cloud of gaseous molecules called "nebula". This nebula begins to collapse. A "protostar" forms out of gas, and planetismals form out of dust, as the cloud continues to condense and flatten. Water, methane, and other ices condense only in outer part of nebula. Solid particles collide and stick together to make planetesimals. Jovians pull in hydrogen and helium gas Formation of Solar System

A Chronology of the Universe and Solar System Big bang; formation of the elements H and He Formation of the solar system (appearance of Ca-Al-rich inclusion) Today 13.7 Gyr 0 Gyr Gyr Late core formation on Mars19 Myr Chondrule Formation2 Myr Lunar Magma Ocean50 Myr Formation of Ca-Al-rich inclusion0 Myr Formation of Achondrite (Vest-like objects)8 Myr Karin Event5.8 Myr Today0 Myr Dinsaur extinction event65 Myr Veritas Event8.2 Myr Lifetime of km-asteroid