Meteorites & Solar System History
ISIS-230 / EOS-230 / Spring 2014
Perkins, Link Classroom #6
Wednesdays, 10:05 - 12:55
Nicholas Gessler

Join us as we explore the origin of our solar system via the science of meteoritics. 
Every day is punctuated by the roar of falling rocks, some seen as fiery meteors in the sky, some unseen, sinking to the ocean's depths and arriving silently on land. 
Over 50,000 meteorites have been registered to date in the global Meteoritical Bulletin Database. 

(Silvia Seceleanu and Ronen Plesser) An exhibit in the Bryan Center mounted and filmed by Anisha Khemlani, Sarah Garland and Sophia Durand (2013).	Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Emily Morino, Jason Lee and ??? .	Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Yuchen Long.	Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Yuchen Long and Kristin Cole.
Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Charlie Thomson.	Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Kristen Cole and Yuchen Long.	Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Kristen Cole.	Astronomy Days at the North Carolina Museum of Natural Sciences (2014). Emily Morino, Jason Lee and ??? .

Meteorites contain micron-size diamond and graphite dust dating back 6 billion years, significantly before our solar system coalesced 4.57 billion years ago.  These rocks take us half-way back to the origin of the Universe 13.7 billion years and origin of our Galaxy 12.7 billion years ago.  The vast majority of meteorites (chondrites) date from a time before the Earth was formed 4.53 billion years ago.  They contain abundant millimeter-size round dust droplets (chondrules) fused by lightning flashing through the coalescing solar nebula.  Chondrites remain as they were formed, undifferentiated from their original structure.  As chondrites further aggregated forming planetesimals, they melted.  More dense minerals like iron fell to the core.  Lighter minerals floated to the crust.  Fragments of these further differentiated bodies (achondrites) are considerably more scarce.  We will work, hands-on, with a wide variety of chondrites and achondrites including specimens from Mars, the Moon, Vesta and other asteroids.

This is the only required textbook. It is authoratative, concise and well illustrated.
Use it as an introduction and guide to the readings on SAKAI and the various resources that are available on the Web.
(Check for discounted copies on Amazon.com).

Additional books that you may find useful.
(Check for discounted copies on Amazon.com).

Descartes and Lavoisier both championed the theory that meteorites were a phenomenon of weather, meteorology, and formed high above the ordinary atmosphere in a flammable layer.  The science of meteoritics began with Ernst Chladni’s publication, “On the Origin of the Pallas Iron and Others Similar to it, and on Some Associated Natural Phenomena”  in 1794.  As he did in his time, we will retrace the cultural and intellectual history of meteoritics from the early accounts in Europe, such as the 1492 fall of a 280-pound stone at Enshsheim, Alsace, to the present hunts, such as the 2012 hunt for a rare carbonaceous chondrite at Sutter’s Mill in California.  Here, in North Carolina, only 29 meteorites are known, the most recent collected in 1934.  None have been reported for nearly 80 years!  We will unearth the historic records to question why.  We may visit collections in the Raleigh Museum of Natural Sciences, known sites of falls and finds, and/or search new localities in order to raise that inventory.*

We will meet in a large computer and multimedia equipped classroom enabling us to actively do research on the Web and to create a resource for North Carolina meteorite information.  We will also experiment with Web-based and PC-based simulations of the origin of the solar system, the ring structures of planets like Saturn, the shepherding influence of moons on smaller particles, the orbits of comets, asteroids and satellites, the odd orbits of Trojan asteroids which lead and follow those of major planets, and the curious wanderings of meteoroids from their ejection from their parent bodies to their arrival on Earth.  These simulations will allow us to run alternative “what if?” scenarios to explain the past and present and to predict the future.

We will investigate different strategies of finding meteorites in the field, in the Antarctic ice, the dry deserts of the Southwest and Northern Africa and in forested regions.  We will learn how to use technologies such as all-sky cameras, Doppler radar and Google Earth to recapture falls and radar and metal locators to recover finds.  We will follow the personal narratives of successful international “hunters.”

We will actively scrutinize a suite of meteorites as they are found, both fresh and weathered, examining hand specimens by eye and by inspection microscope, looking for evidence of their fiery entry through our atmosphere, their fusion crusts and orientation, and their structure as we might encounter them in the field.  We will look more closely at their thin sections, using both inspection and polarizing microscopes.  We may completely characterize some unclassified meteorites under the microprobe and submit them for publication.* 

* These items are on our active “wish list” and we will try to make them happen, but they may be impractical to implement due to logistical, budgetary and administrative constraints.