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Spectral Study of Asteroids and Laboratory Simulated Asteroid Organics
Title
Spectral Study of Asteroids and Laboratory Simulated Asteroid Organics.
Creator
Hargrove, Kelsey, Colwell, Joshua, Fernandez, Yan, Britt, Daniel, Kelley, Michael, University of Central Florida
Abstract / Description
We investigate the spectra of asteroids at near- and mid-infrared wavelengths. In 2010 and 2011 we reported the detection of 3 ?m and 3.2-3.6 ?m signatures on (24) Themis and (65) Cybele indicative of water-ice and complex organics [1] [2] [3]. We further probed other primitive asteroids in the Cybele dynamical group and Themis family, finding diversity in the shape of their 3 ?m [4] [5] [6] and 10 ?m spectral features [4]. These differences indicated mineralogical and compositional...
Show moreWe investigate the spectra of asteroids at near- and mid-infrared wavelengths. In 2010 and 2011 we reported the detection of 3 ?m and 3.2-3.6 ?m signatures on (24) Themis and (65) Cybele indicative of water-ice and complex organics [1] [2] [3]. We further probed other primitive asteroids in the Cybele dynamical group and Themis family, finding diversity in the shape of their 3 ?m [4] [5] [6] and 10 ?m spectral features [4]. These differences indicated mineralogical and compositional variations within these asteroid populations. Also in the mid-infrared region we studied a larger population of asteroids belonging to the Bus C, D, and S taxanomic classes to understand the relationship between any mineralogy and hydration inferred in the visible and near- infrared with the shape, strength, and slope of the 10 ?m emission. We have discovered that at least 3 of the main Bus taxanomic groups (Cs, Ds, and Ss as defined by their visible spectra) clearly cluster into 3 statistically distinct groups based on their 8-13 ?m spectra. Additionally we have attempted to simulate in a laboratory the possible organic compounds we have detected on two asteroids, using various mixtures containing aromatic and aliphatic hydrocarbons. We find that asteroid (24) Themis and (65) Cybele have ?CH2/?CH3 and NCH2/NCH3 ratios similar to our 3- methylpentane, propane, and hexane residues, suggesting that the organics on these asteroids may be short chained and/or highly branched. The ?CH2/?CH3 and NCH2/NCH3 for asteroid(24)Themis are most consistent with the DISM, and some carbonaceous chondrites. The band centers of the C-H stretch absorptions indicate that both asteroids may have aliphatic carriers chemically bonded to electronegative groups (i.e. aromatics), and some that are not. We also detect a 3.45 ?m feature in the spectra of both asteroids that is present in several dense molecular clouds. Our results suggest an interstellar origin for the organics on (24) Themis, and likely (65) Cybele. The differences in the organics of Themis and Cybele are likely related to variations in thermal processing, irradiation and/or formation region in the solar nebula.
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Date Issued
2015
Identifier
CFE0005624, ucf:50201
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0005624
The Impact of Access to Books on the Reading Motivation and Achievement of Urban Elementary Students
Title
The Impact of Access to Books on the Reading Motivation and Achievement of Urban Elementary Students.
Creator
Trimble Spalding, Lee-Anne, Hynes, Michael, Kelley, Michelle, Hoffman, Bobby, Clark, Margaret, Williams, Robert, University of Central Florida
Abstract / Description
The focus of this research was to study the association that reading motivation and reading achievement have with increased access to books provided by the non-profit program Book Trust, could have on urban elementary students, specifically second graders being educated in a large school district in Central Florida. Teacher data collection sheets, the Motivation to Read Profile (MRP): Reading Survey and the Florida Assessment for Instruction in Reading (FAIR) were used to measure the...
Show moreThe focus of this research was to study the association that reading motivation and reading achievement have with increased access to books provided by the non-profit program Book Trust, could have on urban elementary students, specifically second graders being educated in a large school district in Central Florida. Teacher data collection sheets, the Motivation to Read Profile (MRP): Reading Survey and the Florida Assessment for Instruction in Reading (FAIR) were used to measure the aforementioned associations. Findings revealed that increased access to books in these elementary schools did not have a statistically significant impact on reading motivation or reading achievement scores. In addition, teachers' demographic data, such as age, number of years teaching or highest degree held, did not impact their student reading achievement.
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Date Issued
2012
Identifier
CFE0004611, ucf:49933
Format
Document (PDF)
PURL
http://purl.flvc.org/ucf/fd/CFE0004611