Laboratory infrared transmission spectra of individual interplanetary dust particles from 2. 5 to 25 microns

Journal Article · Mon Apr 15 04:00:00 EST 1985 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/163120· OSTI ID:5301387

Sandford, S A; Walker, R M

Dust particles collected in the stratosphere that have chondritic elemental abundances provide a new form of extraterrestrial matter for laboratory study. Spectral transmission measurements from 2.5 to 25 ..mu..m of 26 such particles show that almost all have a dominant 10 ..mu..m silicate absorption feature. Twenty-two of the particles can be grouped into one of three spectral classes referred to as olivines, layer-lattice silicates, and pyroxenes after the minerals that provide the best match to the dust spectra. One particle whose spectrum is dominated by anhydrous oxide minerals was also observed. Of the remaining three particles, one appears to be a mixture of olivines and pyroxenes, but the poor signal-to-noise ratio of the spectrum precludes positive identification, and the third gives no observable absorption bands. Transmission electron microscopy and laser Raman probe studies confirm the silicate mineral identifications. Complementary measurements of large D/H enrichments and solar flare nuclear tracks in some of the same particles confirm that at least some members of each spectral class are extraterrestrial. While not proven, it is likely that all particles measured are interplanetary dust particles (IDPs). The layer-lattice silicates have additional bands at 3.0, 6.0, 6.8, and 11.4 ..mu..m. The first two are probably due to water, and the second two to carbonate minerals. The published infrared spectra of protostars show features similar to those observed in the layer-lattice silicate IDP's, including the 6.8 ..mu..m feature.

• Research Organization: McDonnell Center for the Space Sciences, Washington University Physics Department
• OSTI ID: 5301387
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 291:2; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ALKALINE EARTH METAL COMPOUNDS
COMETS
ELECTRON MICROSCOPY
INFRARED SPECTRA
INTERPLANETARY SPACE
INTERSTELLAR GRAINS
IRON COMPOUNDS
IRON SILICATES
ISOTOPES
MAGNESIUM COMPOUNDS
MAGNESIUM SILICATES
MEASURING INSTRUMENTS
METERS
MICROSCOPY
MINERALS
OLIVINE
OXYGEN COMPOUNDS
PARTICLES
PYROXENES
SCANNING ELECTRON MICROSCOPY
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SPACE
SPECTRA
TRANSITION ELEMENT COMPOUNDS
TRANSMISSION ELECTRON MICROSCOPY