A Reestimate of the Protosolar ( 2 H / 1 H )

A Reestimate of the Protosolar ( 2 H / 1 H ) p ratio from ( 3 He / 4 He ) SW solar wind measurements

Abundances of Deuterium and Helium-3 in the Protosolar Cloud

The mass spectrometric determinations of the isotopic composition of helium in the solar wind obtained from (1) the Apollo Solar Wind Composition (SWC) experiment, (2) the Ion Composition Instrument (ICI) on the International Sun Earth Explorer 3 (ISEE-3), and (3) the Solar Wind Composition Spectrometer (SWICS) on Ulysses are reviewed and discussed, including new data given by Gloeckler and Gei...

New Insights on Saturn’s Formation from Its Nitrogen Isotopic Composition

The recent derivation of a lower limit for the 14N/15N ratio in Saturn’s ammonia, which is found to be consistent with the Jovian value, prompted us to revise models of Saturn’s formation using as constraints the supersolar abundances of heavy elements measured in its atmosphere. Here we find that it is possible to account for both Saturn’s chemical and isotopic compositions if one assumes the ...

Subsolidus Transformation of Amorphous Interstellar Dusts after Injection in a Protoplanetary Disk

Introduction: Infrared observations indicate that a dominant fraction of the condensed matter found in the interstellar medium (ISM) is amorphous (silicates, organic matter, ices). On the other hand, similar spectroscopic studies show that silicates are mainly crystalline in protoplanetary disks [1]. Furthermore, cometary material appears also essentially crystalline [2, 3]. Because the ISM dus...

Molecular nitrogen in comet 67P/Churyumov-Gerasimenko indicates a low formation temperature.

Molecular nitrogen (N2) is thought to have been the most abundant form of nitrogen in the protosolar nebula. It is the main N-bearing molecule in the atmospheres of Pluto and Triton and probably the main nitrogen reservoir from which the giant planets formed. Yet in comets, often considered the most primitive bodies in the solar system, N2 has not been detected. Here we report the direct in sit...