Galaxy Forum New York 2013 - Scarsdale - Denton Ebel

1,526 views

Published on

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
1,526
On SlideShare
0
From Embeds
0
Number of Embeds
621
Actions
Shares
0
Downloads
0
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Galaxy Forum New York 2013 - Scarsdale - Denton Ebel

  1. 1. Asteroids: Science, Resources, Security Denton S. Ebel Scarsdale High School, October 11, 2013 Mg-Ca-Al = R-G-B ~400 micron AOA: Amoeboid Olivine Aggregate 1mm chondrule, cross-polarized light CAI: Ca-, Al-rich Inclusion
  2. 2. What’s out there? What are asteroids? What are they made of? How do we know?
  3. 3. Comet P/Halley 951 Gaspra (ESA Giotto Mission) Comet Wild 2 (US Stardust Mission) Deimos Phobos Comet Borrelly Asteroid Ida and its moon Dactyl Comet C/Hale-Bopp
  4. 4. As of October 6, 2013
  5. 5. Known asteroids: July 1, 2001 Known asteroids: August 14, 2006
  6. 6. Miller fell 1930, Cleburne County, Arkansas Modoc found 1948, Scott Cty., KA
  7. 7. Science
  8. 8. Science Accretion Disks in the Orion Nebula
  9. 9. Orion Nebula in Three Dimensions http://hubblesite.org/newscenter/archive/2001/13/video/a
  10. 10. What is a ‘primitive‘ meteorite ? - chondritic (undifferentiated) - old (4,567.7 million years ± 0.3) - minimally altered by thermal or aqueous processes on parent body - volatile-bearing (e.g., carbonaceous)
  11. 11. COMPONENTS OF CHONDRITES EvidenceChondrules + Matrix + CAIs chondrules Axtell (CV3) McLennon County, Texas found 1943 Ca-, Al-rich inclusions
  12. 12. dark inclusion (breccia fragment) refractory, Ca, Al-rich inclusion (CAI) Mg-, Fe-silicate inclusions (chondrules) Allende
  13. 13. Solar Abundances of the Elements Spectroscopic analyses of the Sun’s photosphere The sun is >99.8% of the solar system’s mass. Spectrum of the Solar Photosphere ~66 elements out of 83 naturally occurring elements are identified ~30 – 35 elements are well determined in the photosphere CI chondrites are “standard rocks” for solar system abundances
  14. 14. Solar Abundances are Well Constrained REE in CI-meteorites (x-axis) and in the Sun (y-axis), (Sneden et al. 2009; Lodders 2003)
  15. 15. Planetary Differentiation Planets were Melted. (radionuclide heating, impacts) Metallic and rocky elements separated from each other (gravity ... it’s the law!) Volatiles surfaced > atmosphere. Rock-loving (lithophile) elements floated. Dense iron-loving (siderophile) elements sank.
  16. 16. Chondritic vs Differentiated Meteorites Chondritic meteorites all have about the same number of Si, Mg and Fe atoms Si, Mg, Fe and O contribute 90 % of the mass of the Earth and chondrites Differentiated meteorites have very different numbers of Si, Mg and Fe atoms Crust => high Si/Mg Mantle => low Fe/Mg Core => very high Fe
  17. 17. Differentiation + Volatile Depletion
  18. 18. Chondrite abundances: Slight volatile depletion
  19. 19. 1 2 4 3 5 Collisions fragmented early planets, exposing iron cores.
  20. 20. Resources
  21. 21. Cruz del Aire Nuevo Leon, Mexico found 1911
  22. 22. Bella Roca Durango, Mexico found 1888 (slice) Iron Meteorite
  23. 23. Ahnighito: 34 tons of iron-nickel meteorite
  24. 24. Ahnighito 30880 mass(kg) 30.88 metric tonnes (mt) element Pt Au Os Ir Ni Co Cu Ru Rh Ir Os Au Re C 34.0393 short tons (tUS) 30.3922 long tons (tUK) Ahnighito microg/g unit unit Total (g) G/mt 8.1 microg/g 1.00E+06 250 8.1 730 ng/g 1.00E+09 23 0.73 1.4 microg/g 1.00E+06 43 1.4 2.1 microg/g 1.00E+06 65 2.1 77.1 4.8 189 4.5 1.65 4.6 3.8 1400 400 0.083 mg/g mg/g microg/g microg/g microg/g microg/g microg/g ng/g ng/g mg/g 1.00E+03 1.00E+03 1.00E+06 1.00E+06 1.00E+06 1.00E+06 1.00E+06 1.00E+09 1.00E+09 1.00E+03 2380848 148224 5836 139 51 142 117 43 12 2563 77100 4800 189 4.5 1.65 4.6 3.8 1.4 0.4 83 (1 ton = 35840.6 oz) (1 tonne (UK) = 35273.96 oz) (1 US ton = 32000.54 oz) oz/t ref 0.29 Huss et al. 1999 LPCS30 #1493 0.03 Huss et al. 1999 LPCS30 #1493 0.05 Huss et al. 1999 LPCS30 #1493 0.08 Huss et al. 1999 LPCS30 #1493 2754 171 6.75 0.16 0.06 0.16 0.14 0.05 0.01 2.96 Terrestrial ore: Pt (g/t) Pd (g/t) Merensky Reef* 3.2 1.4 UG2* 2.4 2.0 * von Gruenewaldt (1977), cited in Cawthorn-SAjS99-PtinBushveld.pdf Platinum in South Africa, South African Journal of Science 95, November/December 1999 The platinum and palladium resources of the Bushveld Complex, by R.G. Caw thorn Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Koeberl et al 1986 NIPR 411: 297-313 Grams/ton
  25. 25. Arecibo RADAR Astronomy Observatory, Puerto Rico
  26. 26. Asteroid Kleopatera raw, delay-Doppler radar images > simulated radar data, from a shape model > Shape model as it would appear illuminated in the plane of the sky > 100 km scale bar > Kleopatera is 220 km long
  27. 27. Security
  28. 28. Impact Field Studies Group http://impacts.rajmon.cz/
  29. 29. best preserved crater on Earth about 50,000 years old about 30 meter diameter iron impactor one km Barringer (Meteor) Crater, Arizona
  30. 30. Fall of Ensisheim meteorite Alsace, November 16, 1492 (woodcut) Fall of Sikhote-Alin meteorite Siberia, February 12, 1947) (painting on stamp issued 1957)
  31. 31. First Earth-grazing Meteoroid Observed 1972 Great Daylight Fireball Aug 10, 1972 2:30 pm local time passed within 57 km (35 mi) of surface traveling at 15 km/sec.
  32. 32. Grand Teton fireball: 1972 movie
  33. 33. Park Forest Meteorite Shower 11:50pm March 26, 2003
  34. 34. Chelyabinsk, Russia 15-February-2013
  35. 35. Chelyabinsk, Russia 15-February-2013 http://www.youtube.com/watch?v=_t1SL2pkWqs
  36. 36. neo.jpl.nasa.gov
  37. 37. neo.jpl.nasa.gov
  38. 38. NEOs coming closer than 5 Lunar/Earth distances ... over time past ... We are in an extraordinary period of increasing ability to find NEOs! As of October 6, 2013 NEOs coming closer than 5 Lunar/Earth distances ... predicted ...
  39. 39. Planetary Protection Deemed Non-essential This presentation, & modern science, would not be possible without US gov. support. (note: Your speaker is not a US Government employee.)
  40. 40. Thank you. American Museum of Natural History, New York c. 1900

×