Meteorites may have contributed amino acids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/ L) molecules. We calculate D/ L ratios for seven biological, α-hydrogen, protein amino acids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that amino acids in meteorites do not necessarily underg...

The presence of nonprotein α-dialkyl-amino acids such as α-aminoisobutyric acid (α-AIB) and isovaline (Iva), which are considered to be relatively rare in the terrestrial biosphere, has long been used as an indication of the indigeneity of meteoritic amino acids. However, recent work showing the presence of α-AIB and Iva in peptides produced by a widespread group of filamentous fungi indicates ...

We present here the first infrared spectra of meteoritic SiC grains. The mid-infrared transmission spectra of meteoritic SiC grains isolated from the Murchison meteorite were measured in the wavelength range 2.5–16.5 μm, in order to make available the optical properties of presolar SiC grains. These grains are most likely stellar condensates with an origin predominately in carbon stars. Measure...

A chlorite “hand-bag” belonging to the once-called “intercultural style” production, currently on exhibit in the NationalArchaeological Museum, Tehran, is described focusing attention, for the first time, to the peculiar wear traces clearlyvisible on the handle and along its contour. The strong wear suggests that the hand-bag was suspended for a long time ona cord; and that in this setting it w...

Achiral meteoritic amino acids, glycine and alpha-methylalanine, with hydrogen isotope (D/H) chirality, acted as the source of chirality in asymmetric autocatalysis with amplification of ee to afford highly enantioenriched 5-pyrimidyl alkanols.

available online at http://meteoritics.org 239 © The Meteoritical Society, 2005. Printed in USA. The formation of the Widmanstätten structure in meteorites J. YANG* and J. I. GOLDSTEIN Department of Mechanical and Industrial Engineering, College of Engineering, University of Massachusetts, Amherst, Massachusetts 01003, USA *Corresponding author. E-mail: [email protected] (Received 16 October...