Meteorites and Their Parent Planets

QB755.M465 1999, 2nd Ed, Harry Y. McSween, Jr., Cambridge University Press

• Meteoroid - orbiting object in space

• Meteor - object passing through atmosphere

• Meteorite - recovered fragment

• Chondrite - 86%, silicate and oxide minerals, looser sediment

• Achondrite - 8%, igneous rock, partial melting and crystalization

• Iron - 5%, nickle-iron

• Stony Iron - 1%, mixed iron and rock

• Willamette Stone - 12700 kg iron

• maximum 72 km/s retrograde, typically 10 to 30 km/s prograde
• p22 fig 1.13: meteors carried through blue ice to ablate in katabatic winds in front of mountains, a few thousands to a million years later

• Amor outside Earth's radius, or overlap Apollo > 1 year Aten < 1 year

• p43 Rubidium to strontium isotope ratios yield age
• p48 Element ratios the same as the Sun, though less gasses and more lithium

Connection to Asteroids

• -p79 1959 Pribam near Prague tracked by several cameras intended for satellite tracking
• 1964-1974 Smithsonian's Prarie Network, 16 cameras in 500 km radius of SE Nebraska
  • tracked hundreds, recovered "Lost City" in Oklahoma
• Canadian network recovered "Innisfree" in Alberta
• Asteroid types: S - chondrites, C - carbonaceous, D, P - dark
• p120 ultramafic, like earth mantle basalt, olivine and pyroxene, rich in Mg and Fe
• p192 iron phase diagram. Kamacite lower temperature BCC crystal, Taenite higher temperature (or more nickel) FCC crystal
  • Widmanstätten patterns from crystal growth
• p243 Fig 8.6, spall ejecta from planets Jay Melosh