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The importance of experiments: Constraints on chondrule formation models |
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| Authors: | Steven J DESCH Melissa A MORRIS Harold C CONNOLLY Jr Alan P BOSS |
| Institution: | 1. School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, Arizona 85287–1404, USA;2. Kingsborough Community College and the Graduate Center of the City University of New York, 2001 Oriental Boulevard, Brooklyn, New York 11235–2398, USA;3. American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024–5192, USA;4. Lunar and Planetary Laboratory, 1629 E. University Blvd., The University of Arizona, Tucson, Arizona 85721–0092, USA;5. Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Rd NW, Washington, DC 20015–1305, USA |
| Abstract: | Abstract— We review a number of constraints that have been placed on the formation of chondrules and show how these can be used to test chondrule formation models. Four models in particular are examined: the “X‐wind” model (sudden exposure to sunlight <0.1 AU from the proto‐Sun, with subsequent launching in a magnetocentrifugal outflow); solar nebula lightning; nebular shocks driven by eccentric planetesimals; and nebular shocks driven by diskwide gravitational instabilities. We show that constraints on the thermal histories of chondrules during their melting and crystallization are the most powerful constraints and provide the least ambiguous tests of the chondrule formation models. Such constraints strongly favor melting of chondrules in nebular shocks. Shocks driven by gravitational instabilities are somewhat favored over planetesimal bow shocks. |
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