Dr. Henry Throop / University of Colorado Astronomy 1110 June 26, 2000 Lecture 16: Formation of the Solar System Announcements ------------- HW #4 -- due Wednesday, but I'll return any turned in on Tuesday in time for Exam #2 Final: will be cumulative Exam #2: covers giant planets, rings, satellites, formation of SS, collisions, ESP's Perhaps a bit of current events Observing tonight: maybe?? Formation of SS --------------- Key things to consider Planets move in same direction Planets move, spin the same Satellites move, spin same as planets There are some exceptions (Retrograde spins -- not retrograde motion!) Planet properties generally move Less dense further out More gas further out Bigger Futher apart German philosopher Immanuel Kant in 1755 hypothesized the origin of the solar system as beginning with a rotating gaseous nebula out of which condensed globular bodies that became the sun and planets---all revolving in the same direction. Essentially the same theory, now called "the nebular hypothesis" was proposed by the French mathematician Laplace in 1796. Start off with a cloud 1. Cloud collapses radially (due to gravitation) 2. Cloud heats up as it collapses ( 3. Cloud spins faster as it collapses Light & Telescopes ------------------ Build a telescope w/ laser beam splitter & chalk Heliostat 16/18": look inside them Differences between telescopes Magnification Brightness Wavelength Instrumentation Stability Size (s/c?) Newtonian (lenses -- refractor) All others (mirrors -- reflector) Heliostat --------- Image of sun Sunspots -- colder Chinese had sunspot records UV -- can see it Sun rotates -- takes 1 month. Very slow planet -- surprising. Slow because of mag. field. Big magnet, rotate it. Like trying to turn a generator spindle. Telescopes Mercury Venus Moon Moon phases -- like on exam #1 Mercury phases -- work with partner to figure out inner v. outer planet phases? Orion disks ----------- Collab q's ---------- 1. What if