New for 2001-BCC9804 Silicate Skeletal Remains of Cometary Debris !

by S. Ray DeRusse originally posted Summer of 2002.
And see John C. Brandt, COMETS, Scientific American 1981.

All Cometary sample material for display not for sale until further notice.

  The relationship between stellar matter (stars) and cometary matter (comets), is well documented, [remote spectral data and remote sensing]. We subscribe to the icy conglomerate model, Jeffrey's and Robbins; Discovering Astronomy, 1981, pp 108-109,  "Very near the sun, atomic emissions due to metals such as sodium, calcium, silicon, and iron, are also observed. These are presumably the result of vaporization of dust particles by the intense solar heat, followed by excitation of the vapor of the Sun's radiation; these emissions are additional evidence of the presence of solid material in the cometary body." Therefore, Cometary material is
   composed of amorphous and crystalline stellar grain debris from stars. However, the volatile material which escapes transformation into heavier elements during nuclear fusion in and adjacent to the central core of the star is expelled outward some distance D from the star, and at the proper distance, the temperature and pressure (atomic vibrational states) is ideal for molecular bonding of the volatile elements and accretion with the amorphous and crystalline material.
    The bonding of these elements results in the formation of  PAH masses and complex CH, CH2, CO, CN, NH, and NH2, and also of ionized molecule based gases, and as the matter moves further away from the nuclear furnace, a transformation from gas to liquid to frozen ices interwoven within the crystalline and amorphous stellar matter occurs.
    This is one of the same reasons (of several), there has never been any naturally occurring water or ice on the Moon. The vibrational states of the outer electron for these atoms must be ideal for a bond to occur. The vibrational state is too high (hot) on one side of the Moon and too low (cold) on the other. In order to have ice on the Moon you first have to have an H2O bond (water) that can occur even if just for a nanosecond. But the T and P conditions necessary are not present. Remember also that there is very little opportunity for the volatile elements to exist on the surface of the Moon because gravity is 1/6 that of Earth, this makes the mass density of C on the Moon equivalent to H on Earth. In other words everything above the atomic number of 6 will exist in negligible quantities on the Moon. Contrary to popular belief by some in the Planetary Sciences, cometary material and masses are not friable and loosely held together but in fact even the icy volatile material is very densely compacted in and around the silicate matter.
  
 
 
    The individual grain composition can easily be seen above such as the enstatite grain at the upper left (peach colored).  The interesting thing here is not so much the composition of the individual sub-mm grains, which is to be expected in a stellar/cometary environment, as the grain interpenetration and accretion of multiple phases and components to form a single grain, which can be seen in a wider field of view below. Photomicrograph details taken from two thin sections shown above. Dark areas between grains include but are not limited to oxides and crystalline solutions of Al, Fe, Mg, Ca.  Courtesy, Molecular Expressions.
  
     Wider field of view of cometary grains from BCC9804. The extraordinary crystalline variation in the stellar environment is unbelievably complex. Note the almost even distribution of smaller dust size crystals both, complete grains and fragments due to collisions and compaction and form the interstitial cementious bonding matrix holding the larger grains in place. This Cometary sample has a high density and is very cohesive.  Graphs by Molecular Expressions.

    The scientist or student interested in stellar/cometary silicates may want to pay special attention to this image. Notice the zone of well sorted smaller crystalline silicates beginning at about the center of the above frame and extending upwards towards the left at ~ 60 degrees. These distinct crystal fragments in this region are very small and would measure about <.10-.20mm. As is evident many larger grains are deformed at the grain walls to accommodate its nearest neighbor, this can be readily seen in the upper right hand corner of this photomicrograph. Courtesy Molecular Expressions. The dark shadowy material unfortunately is contamination.

More Photomicrographs of this sample.

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