Astronomy 1021 Lecture Notes - Lecture 10: Protoplanetary Disk, Volcanism, Radiometric Dating

• School: Western University
• Department: Astronomy
• Course: Astronomy 1021
• Professor: Jan Cami

Document Summary

Planetary orbits are mostly circular and fall on the same plane. Nebular hypothesis: rst proposed by immanuel kant and says that the solar system is formed from the gravitation al collapse of an interstellar cloud of gas. Particles tend to get kicked most often in direction of overall angular momentum. Spinning cloud fattens into disk as it shrinks. Planets formed in the at spinning disk. In a gravitational collapse a particle loses its gravitational potential energy. Gravitational collapse always results in spinning, attening, and getting of the solar nebula. On this scale, 0 degrees corresponds to 0 energy. 0 kelvin is thus the lowest possible temperature and is known as the absolute zero, since negative energies are not possible. Degrees kelvin = degrees celcius + 273. 15. The way in which molecules are held together in a substance can change and this the same material can exist in different states. Temperatures in a protoplanetary disk vary with distance to the center.