Article Abstract:
Research on the Murchison meteorite by M.H. Engel and S.A. Macko suggests that the Solar System was formed with a bias for left-handed amino acids. Engel and Macko examined individual amino-acid enantiomers in the meteorite and confirmed their earlier findings that there is an excess of L-alanine over D-alanine. Two other pieces of research on the Murchison meteorite confirm the enantiomeric excesses which could indicate a link between extraterrestrial organic molecules and the origins of life on earth.
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Article Abstract:
The dismissal of a carbonaceous chondrite meteor as the cause of the Tunguska crater is based on an unrealistic drag coefficient and heating load. A recalculation of the heating load and drag coefficient reveals that a carbonaceous chondrite meteor of sufficient size could have released its energy low enough to cause the crater and since that type is the most common meteor to enter Earth's atmosphere, it is logically the most likely cause of the crater.
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Article Abstract:
The explosion over the Siberian taiga near the Tunguska river on Jun 30, 1908 was the result of a stony meteorite fragmenting in the atmosphere. It was long believed that a meteorite could deliver as much energy as this one did and not leave a crater only if it was of very low density. However, an ordinary stony meteorite may have acted in just this way had it undergone cataclysmic fragmentation fueled by aerodynamic action.
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