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A Clarification. The Constellation program was for space exploration and lunar/planetary science. It was not going to be prospecting for water! (As we learned last week, that wouldn’t make sense.)
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A Clarification The Constellation program was for space exploration and lunar/planetary science. It was not going to be prospecting for water! (As we learned last week, that wouldn’t make sense.) The cancellation of Constellation doesn’t affect humanity’s fresh water problems, but it means that for the first time in about 50 years, the U.S. will not have a government-run manned launch vehicle. We will be dependent upon other government agencies, and eventually private industry, to get astronauts to and from orbit.
The Moon • The only celestial body people have walked on (other than Earth) • The only celestial body for which we have radiometric ages (other than Earth and meteorites) • The only celestial body for which we have seismic data (other than Earth) • Only 1 geologist has been there • We’ve only explored a tiny amount of the surface • 6 landings • longest sortie <20 km
Lunar contributions to Planetary Science • “Pristine surface”, in Earth’s neighborhood • Absolute age determinations (Apollo and Soviet samples) • Calibration for relative age dates used throughout the Solar System • Heavy Bombardment
Dating • Absolute • Radiometric age dating • Compare (radioactive) parent & (radiogenic) daughter isotopes with non-radiogenic isotopes • Look at different crystals, different isotopes, to get a good estimate • Relative • Concept: older surface has had more time to be hit by meteorites • Complications: exhumation, “secondary craters”
Earth’s surface: types of rocks Images from http://www.fas.org/irp/imint/docs/rst/Sect2/Sect2_1.html, http://www.learner.org/acourses/essential/earthspace/session3/closer1.html, http://www.americansouthwest.net/arizona/bill_williams_river/bwrocks_l.html
Surface Processes • Erosion • Tectonics • Volcanism • Impacts Images from http://fireflyforest.net/firefly/2005/11/12/aerial-view-of-the-grand-canyon/, http://www.scientificamerican.com/article.cfm?id=geologists-link-the-great, http://rst.gsfc.nasa.gov/Sect18/Sect18_1.html, and http://users.forthnet.gr/ath/nikolas_c/tectonic_geoology.htm
The Moon’s surface Images from http://www.lpi.usra.edu/lunar/missions/clementine/images/ and http://www.lpi.usra.edu/lunar/missions/apollo/apollo_17/experiments/lnp/
New lunar images http://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/apollosites.html
Earth’s interior http://www.gly.uga.edu/railsback/1121CrMaLiAsthenosphere.jpeg
Earth’s interior, cont. P wave S wave http://geophysics.ou.edu/solid_earth/notes/seismology/seismo_interior/seismo_interior.html
The Moon’s interior http://www.astro.psu.edu/users/niel/astro1/slideshows/class41/slides-41.html
Earth’s atmosphere * variable gases From http://www.physicalgeography.net/fundamentals/7a.html
The Greenhouse Effect http://www.fas.org/irp/imint/docs/rst/Sect16/Sect16_2.html
http://geophysics.ou.edu/solid_earth/notes/seismology/seismo_interior/seismo_interior.htmlhttp://geophysics.ou.edu/solid_earth/notes/seismology/seismo_interior/seismo_interior.html