Helium in Lunar Samples Analyzed by High‐Resolution Stepwise Etching: Implications for the Temporal Constancy of Solar Wind Isotopic Composition

2003 ◽  
Vol 597 (1) ◽  
pp. 602-614 ◽  
Author(s):  
Veronika S. Heber ◽  
Heinrich Baur ◽  
Rainer Wieler
Keyword(s):  
Solar Wind ◽  
High Resolution ◽  
Isotopic Composition ◽  
Lunar Samples

scholarly journals A 15N-Poor Isotopic Composition for the Solar System As Shown by Genesis Solar Wind Samples

Science ◽  
2011 ◽  
Vol 332 (6037) ◽  
pp. 1533-1536 ◽  
Author(s):  
B. Marty ◽  
M. Chaussidon ◽  
R. C. Wiens ◽  
A. J. G. Jurewicz ◽  
D. S. Burnett
Keyword(s):  
Solar Wind ◽  
Solar System ◽  
Isotopic Composition

scholarly journals High-resolution measurements of atmospheric molecular hydrogen and its isotopic composition at the West African coast of Mauritania

2012 ◽  
Vol 9 (12) ◽  
pp. 18799-18829
Author(s):  
S. Walter ◽  
A. Kock ◽  
T. Röckmann
Keyword(s):  
High Resolution ◽  
Isotopic Composition ◽  
Molecular Hydrogen ◽  
H2 Production ◽  
West African ◽  
Mixing Ratio ◽  
The West ◽  
Isotopic Signatures ◽  
West African Coast ◽  
African Coast

Abstract. Oceans are a net source of molecular hydrogen (N2) to the atmosphere, where nitrogen (N2) fixation is assumed to be the main biological production pathway besides photochemical production from organic material. The sources can be distinguished using isotope measurements because of clearly differing isotopic signatures of the produced hydrogen. Here we present the first ship-borne measurements of atmospheric molecular H2 mixing ratio and isotopic composition at the West African coast of Mauritania (16–25° W, 17–24° N). This area is one of the biologically most active regions of the world's oceans with seasonal upwelling events and characterized by strongly differing hydrographical/biological properties and phytoplankton community structures. The aim of this study was to identify areas of H2 production and distinguish H2 sources by isotopic signatures of atmospheric H2. Besides this a diurnal cycle of atmospheric H2 was investigated. For this more than 100 air samples were taken during two cruises in February 2007 and 2008, respectively. During both cruises a transect from the Cape Verde Island towards the Mauritanian Coast was sampled. In 2007 additionally four days were sampled with a high resolution of one sample per hour. Our results clearly indicate the influence of local sources and suggest the Banc d'Arguin as a pool for precursors for photochemical H2 production, whereas N2 fixation could not be identified as a H2 source during these two cruises. With our experimental setup we could demonstrate that variability in diurnal cycles is probably influenced and biased by released precursors for photochemical H2 production and the origin of air masses. This means for further investigations that just measuring the mixing ratio of H2 is insufficient to explain the variability of a diurnal cycle and support is needed, e.g. by isotopic measurements. However, measurements of H2 mixing ratios, which are easy to conduct online during ship cruises could be a helpful tool to easily identify production areas of biological precursors such as VOC's for further investigations.

Concentration and Isotopic Composition of Carbon and Sulfur in Apollo 11 Lunar Samples

Science ◽  
1970 ◽  
Vol 167 (3918) ◽  
pp. 541-543 ◽  
Author(s):  
I. R. Kaplan ◽  
J. W. Smith
Keyword(s):  
Isotopic Composition ◽  
Lunar Samples

Solar Wind Helium Isotopic Composition from SWICS/Ulysses

1995 ◽  
pp. 61-64
Author(s):  
R. Bodmer ◽  
P. Bochsler ◽  
J. Geiss ◽  
R. Von Steiger ◽  
G. Gloeckler
Keyword(s):  
Solar Wind ◽  
Isotopic Composition ◽  
Helium Isotopic Composition

scholarly journals High‐resolution food webs based on nitrogen isotopic composition of amino acids

2014 ◽  
Vol 4 (12) ◽  
pp. 2423-2449 ◽  
Author(s):  
Yoshito Chikaraishi ◽  
Shawn A. Steffan ◽  
Nanako O. Ogawa ◽  
Naoto F. Ishikawa ◽  
Yoko Sasaki ◽  
...  
Keyword(s):  
Amino Acids ◽  
High Resolution ◽  
Isotopic Composition ◽  
Food Webs ◽  
Nitrogen Isotopic Composition

Isotopic composition of xenon and krypton in the lunar soil and in the solar wind

1971 ◽  
Vol 10 (2) ◽  
pp. 199-216 ◽  
Author(s):  
F.A. Podosek ◽  
J.C. Huneke ◽  
D.S. Burnett ◽  
G.J. Wasserburg
Keyword(s):  
Solar Wind ◽  
Isotopic Composition ◽  
Lunar Soil

The Isotopic Composition of Iron in the Solar Wind: First Measurements with the MASS Sensor on the [ITAL]Wind[/ITAL] Spacecraft

1997 ◽  
Vol 474 (1) ◽  
pp. L69-L72 ◽  
Author(s):  
M. Oetliker ◽  
D. Hovestadt ◽  
B. Klecker ◽  
M. R. Collier ◽  
G. Gloeckler ◽  
...  
Keyword(s):  
Solar Wind ◽  
Isotopic Composition ◽  
Mass Sensor

The chlorine-isotopic composition of lunar KREEP from magnesian-suite troctolite 76535

2020 ◽  
Vol 105 (8) ◽  
pp. 1270-1274
Author(s):  
Francis M. McCubbin ◽  
Jessica J. Barnes
Keyword(s):  
Isotopic Composition ◽  
Melt Inclusions ◽  
Melt Inclusion ◽  
Isotopic Fractionation ◽  
Magma Ocean ◽  
Geochemical Composition ◽  
Isotopic Compositions ◽  
Stable Isotopic ◽  
Lunar Samples

Abstract We conducted in situ Cl isotopic measurements of apatite within intercumulus regions and within a holocrystalline olivine-hosted melt inclusion in magnesian-suite troctolite 76535 from Apollo 17. These data were collected to place constraints on the Cl-isotopic composition of the last liquid to crystallize from the lunar magma ocean (i.e., urKREEP, named after its enrichments in incompatible lithophile trace elements like potassium, rare earth elements, and phosphorus). The apatite in the olivine-hosted melt inclusion and within the intercumulus regions of the sample yielded Cl-isotopic compositions of 28.3 ± 0.9‰ (2σ) and 30.3 ± 1.1‰ (2σ), respectively. The concordance of these values from both textural regimes we analyzed indicates that the Cl-isotopic composition of apatites in 76535 likely represents the Cl-isotopic composition of the KREEP-rich magnesian-suite magmas. Based on the age of 76535, these results imply that the KREEP reservoir attained a Cl-isotopic composition of 28–30‰ by at least 4.31 Ga, consistent with the onset of Cl-isotopic fractionation at the time of lunar magma ocean crystallization or shortly thereafter. Moreover, lunar samples that yield Cl-isotopic compositions higher than the value for KREEP are likely affected by secondary processes such as impacts and/or magmatic degassing. The presence of KREEP-rich olivine-hosted melt inclusions within one of the most pristine and ancient KREEP-rich rocks from the Moon provides a new opportunity to characterize the geochemistry of KREEP. In particular, a broader analysis of stable isotopic compositions of highly and moderately volatile elements could provide an unprecedented advancement in our characterization of the geochemical composition of the KREEP reservoir and of volatile-depletion processes during magma ocean crystallization, more broadly.

Implantation of ions escaping the atmosphere of Mars within the regolith of Phobos, and Phobos’ surface ion weathering

2020 ◽  
Author(s):  
Quentin Nénon ◽  
Andrew R Poppe ◽  
Ali Rahmati ◽  
James P McFadden
Keyword(s):  
Solar Wind ◽  
Atomic Oxygen ◽  
The Moon ◽  
Ion Composition ◽  
Atmospheric Escape ◽  
The Past ◽  
Lunar Samples ◽  
Singly Charged

<p>Mars has lost and is losing its atmosphere into space. Strong evidences of this come from the observation of planetary singly charged heavy ions (atomic oxygen, molecular oxygen, carbon dioxide ions) by Mars Express and MAVEN. Phobos, the closest moon of Mars, orbits only 6,000 kilometers above the red planet’s surface and is therefore a unique vantage point of the planetary atmospheric escape, with the escaping ions being implanted within the regolith of Phobos and altering the properties of the moon’s surface.</p> <p>In this presentation, we aggregate all ion observations gathered in-situ close to the orbit of Phobos by three ion instruments onboard MAVEN, from 2015 to 2019, to constrain the long-term averaged ion environment seen by the Martian moon at all longitudes along its orbit. In particular, the SupraThermal and Thermal Ion Composition (STATIC) instrument onboard MAVEN distinguishes between solar wind and planetary ions. The newly constrained long-term ion environment seen by Phobos is combined with numerical simulations of ion transport and effects in matter.</p> <p>This way, we find that planetary ions are implanted on the near side of Phobos (pointing towards Mars) inside the uppermost tens of nanometers of regolith grains. The composition of near-side grains that may be sampled by future Phobos sample return missions is therefore not only contaminated by planetary ions, as seen in lunar samples with the terrestrial atmosphere, but may show a unique record of the past atmosphere of Mars.</p> <p>The long-term fluxes of planetary ions precipitating onto Phobos are so intense that these ions weather the moon’s surface as much as or more than solar wind ions. In particular, Martian ions accelerate the long-term sputtering and amorphization of the near side regolith by a factor of 2. Another implication is that ion weathering is highly asymmetric between the near side and far side of Phobos.</p>

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