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12 - Formation & Evolution of the Solar System. 4 Terrestrial Planets. Mercury. Venus. Earth. Mars. 4 Jovian Planets. (ice giants). Uranus Neptune. Jupiter Saturn. (gas giants). Terrestrial Mercury Venus Earth Mars Small Diameters Small Masses
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4 Terrestrial Planets Mercury Venus Earth Mars
4 Jovian Planets (ice giants) Uranus Neptune Jupiter Saturn (gas giants)
Terrestrial Mercury Venus Earth Mars Small Diameters Small Masses Large Densities Few Moons No Rings Rock & Metals Jovian Jupiter Saturn Uranus Neptune Large Diameters Large Masses Small Densities Many Moons Rings H, He, (C, N. O) Differences in the 2 Main Classes of Planets To Sun
Numerous moons, asteroids, comets, “Kuiper belt objects”, “centaurs”, and Pluto (actually a KBO) Ganymede Hyperion Titan Eros Kuiper Belt Hale-Bopp
Formation & Evolution of the Solar System Planets, asteroids (minor planets), Kuiper Belt Objects (another form of minor planet) General Structure
Planets gradually form out of the rotating disk of gas & dust Beyond the “frost line” ice can condense, allowing more massive planets to form Nebular Model Refractories (rock, metal) volatiles (ices & gas) and refractories
Two possible sequences of formation of terrestrial (rocky) planets: • Merge homogeneous collection of planetesimals, then differentiate • Form planets while condensation is still happening
Asteroids, also called Minor Planets Same as planetesimals that formed the terrestrial planets • Meteorites are pieces of asteroids that have made it to Earth. Type: • Stony • Iron • Stony-Iron • Some stony ones • contain organics Ida, with its moon Dactyl
Kuiper Belt ObjectsTrans-Neptunian Objects Eris & Dysnomia (official names) (Eris) Eris (larger than Pluto)
Comets Comet Hale-Bopp C/2002 Q2 NEAT
Comet Dust Silicates “CHON” Comet Gases H, O, OH, CN, CH, NH2, C2, C3, CO, CH3OH (methanol), HCN (hydrogen cyanide), H2O, H2S, CS, H2CO (formaldehyde), CH3CN, HNC, etc. Giotto spacecraft image of the nucleus of Comet Halley (1986)
Interplanetary Dust Particles shed by comets & collected in Earth’s atmosphere - silicates & organics
Stardust Spacecraft @ Comet Wild 2 in Jan. 2004Returned to Earth with Dust Sample in Jan. 2006 Captured forsterite (Mg2SiO4) grain!
Comet 73P/Schwassmann-Wachmann 3 Fragmented in 1995 Seen again in 2000
2006 - Returned In Many Pieces! Deep Impact-like analysis in preparation - Sitko et al.
Eruption of Comet 17P/Holmes in 2007 Deep Impact-like analysis in preparation - Lisse et al.
While many details are not yet known: • basics of the formation of the SS is understood • chemical/mineral content of early SS becoming known • no unusual or “freak” events necessary • the early SS had organics • we see the same things around other stars • We expect planetary systems to be common, and many may be similar to our own