Astronomical relevance of materials from earth and space: a laboratory study
Rauf, Kani Mustafa
The present study used scanning and transmission electron microscopy, energy dispersive analysis of X-rays (EDAX) and spectroscopy (FTIR, UV-Visible and fluorescence) to examine terrestrial materials of possible astronomical significance (Oedogonium sp., Enteromopha intestinalis, Pelvetia canaliculata, Fucus vesiculosus, Bacillus cereus, Staphyllococcus aureus, poppy seed, chlorophylls 'a' and 'b', Panicum maximum, anthracite, bituminous coal, naphthalene), the Tagish lake and Carancas meteorites, a Kerala red rain sample and stratospheric air particles collected at altitudes of 38-41 km. The study was designed to determine if any of the terrestrial samples could be proposed as an effective model for the interpretation of astronomical spectroscopic observations. The study also set out to search for evidence to shed light on the origin of these meteorites, red rain and stratospheric air particles. The spectra of all the terrestrial samples (including the meteorites) exhibited absorptions in the Mid-IR region, similar to astronomical features displayed by a variety of galactic sources. Algae (Odeogonium sp.) in particular produced the largest number of absorption peaks, most of which matched those of the astronomical emission spectra of PPNe and also the UIBs. Based on these observations, algae could be defended as a biological model for the interpretation of UIBs and PPNe, and a potential candidate for interstellar material. Coal and semi anthracite, that can be regarded as steps in the degradation of biomaterial, preserve the UIB-PPNe spectral features to varying degrees. The results are consistent with the panspermia theory of Hoyle and Wickramasinghe. UV-Visible studies were also conducted on all these materials. The main absorption feature was one close to 217.5 nm (2175 A). The normalized (averaged) spectrum of the whole sequence of biological materials and their degradation products absorption feature at 217.5 nm (2175 A) further support the contention that aromatic molecules in biological materials are responsible for the interstellar absorption feature centred at 217.5 nm.
49 references, page 1 of 5
views in local repository
downloads in local repository
The information is available from the following content providers: