The more we look among the stars and galaxies, the weirder things seem to get. Even space itself is puzzling, for example. Recent studies suggest that the fabric of the universe stretches more than 150 billion light-years across -- in spite of the fact that the cosmos is 13.7 billion years old….Learn more mystery…!

This paper discuss the origin of the isotopic fractionation of hydrogen, nitrogen, oxygen and carbon observed in comets. These could be the remnants of the chemistry in dense ISM. The authors present chemo-dynamical model of a dense core which can plausibly account for the isotopic fractionation of these elements in comets.

This paper presents measurements of the nitrogen fractionation in both HCN and CN towards the Jupiter-like comet 17P/Holmes. Previous observations of Hale-Bopp indicated that the isotopic 15N/14N ratio in HCN was similar to that observed on Earth. On the other hand, the 15N/14N ratio in CN -- which is formed from HCN in cometary atmospheres -- was terrestrial. The present observations and re-analysis of the Hale-Bopp data, taking into account the opacity of HCN lines, suggest that HCN and CN have indeed the same non-terrestrial composition in both comets.