Starting Line 1. turn in Homework #1 2. book check 3. topic selections Planetary Sciences
Asteroids 2003 semimajor axis Planetary Sciences
Planetary Sciences
Asteroids 2003 semimajor axis Planetary Sciences
Asteroids 2009 semimajor axis Jupiter Trojan Asteroids Planetary Sciences
Lagrangian Points where objects feel no net force in rotating frame: gravitational force of two masses cancels centrifugal force because of rotation 5 per two body system Trojan asteroids at Jupiter (~3000), Mars (4), Neptune (6) small moons at Sat/Tethys (Telesto+Calypso) and Sat/Dione(Helene+Polydeuces) Earth orbiting spacecraft L1 L2 L3 unstable … L4 L5 stable SOHO WMAP Planetary Sciences
Planetary Sciences
KBOs and Comets 2003 KBOs red: classical KBOs white: Plutinos magenta: scattered disk orange tri: Centaurs cyan tri: “unusual” COMETS solid blue sqr: numbered open blue squ: others Planetary Sciences
KBOs and Comets 2009 KBOs red: classical KBOs white: Plutinos magenta: scattered disk orange tri: Centaurs cyan tri: “unusual” COMETS solid blue sqr: numbered open blue squ: others more objects, not just pencil beams, pencil beams have spread, blue planets have moved,Pluto/KBOs have moved Planetary Sciences
KBOs and Comets 2009 Plutinos/TNOs 1093 known Pluto Quaoar Ixion Varuna Orcus Centaurs/SDOs 242 known Chiron Sedna Nessus Asbolus Eris TNO = Trans Neptunian Object SDO = Scattered Disk Object Planetary Sciences
TNOs/SDOs and Friends Hydra Nix Planetary Sciences
Pluto Has 3 Moons! Nix = mother of Charon … Hydra = guardian of underworld with 9 heads Planetary Sciences
The “New” Solar System KBO Plutino Dwarf Planet Eris Plutoid but wait, there’s more … Planetary Sciences
The Outer Limits Planetary Sciences
Hyakutake and Hale-Bopp Planetary Sciences
Comet SOHO-6 white spot is size of Sun … tail 2X as long as Sun’s diameter Planetary Sciences
Asteroids, KBOs, Oort Cloud Asteroid Belt Kuiper Belt Oort Cloud Orbital a 2.1 – 3.3 AU 30 – 100+ AU ~ 50,000 AU Orbital e 0.0 – 0.4 medium nearly 1.0 Orbital i low medium any! Composition rocky rocky/icy icy/dusty Planetary Sciences
Comet Exploration Exploration Halley Giotto, Vega Tempel 1 Deep Impact … dropped a bullet Wild 2 Stardust … sample return 2006 Stardust results indicate some grains from other stars captured from Wild 2 into aerogel but most grains were (surprisingly) from both hot and cold environments in our early Solar System conclusion: early SS was a mess with radical transport of cometary material at early stages Planetary Sciences
Comet Damage Planetary Sciences
Comet Damage Planetary Sciences
Comet Damage: Tunguska 1908 Planetary Sciences
Asteroids … Bye Bye Dinosaurs 65 million years ago Planetary Sciences
Game Over? Planetary Sciences
Location, Location, Location Planetary Sciences
Jovians Good or Bad? Planetary Sciences
Disk: Protostellar or Debris? Planetary Sciences
Fomalhaut Planet background star movie Planet is just inside ring edge / orbital period 872 years background star movie Planetary Sciences
Homework #2 Calculate the space densities in units of #objects per cubic km of Main Belt asteroids, KBOs, and Oort Cloud comets. Assume the following: a. Asteroid Main Belt is a disk containing 106 objects stretches from 2 AU to 3 AU and is 1 AU thick b. Kuiper Belt is a disk containing 105 objects stretches from 30 AU to 100 AU and is 10 AU thick c. Oort Cloud is a sphere containing 1012 objects stretches from 20,000 AU to 100,000 AU DUE THURSDAY, JANUARY 22 Planetary Sciences