February 22, 2001 . Filed under ... Terrestrial helium is mostly helium-4, while extraterrestrial helium is mostly helium-3. "These things form in carbon stars. That's what's excitingWeb
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9 MARCH 2001 VOL 291 SCIENCE A Short Duration of the Cretaceous-Tertiary Boundary Event: Evidence from Extraterrestrial Helium-3 S. Mukhopadhyay,1* K. A. Farley,1 A. Montanari2 Analyses of marine carbonates through the interval 63.9 to 65.4 million years ago indicate a near-constant flux of extraterrestrial …Web
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The accretion of extraterrestrial noble gases such as He and Ar was discussed by Becker et al. (2001), who reported high concentrations of extraterrestrial He ( 3 He ET ) in PTB rocks from Japan ...Web
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Mukhopadhyay, S., Farley, K. A. & Montanari, A. A short duration of the Cretaceous-Tertiary boundary event: evidence from extraterrestrial helium-3. Science …Web
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In 2001, Dr. Becker and her colleagues said they had found the calling card of a killer meteor: soccer- ball-shaped molecules known as buckyballs that contained helium with an extraterrestrial ...Web
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Mukhopadhyay S, Farley KA, Montanari A. A short duration of the Cretaceous-Tertiary boundary event: Evidence from extraterrestrial Helium-3. Science. 2001b; …Web
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The helium we obtained from Bed 25 samples is reasonable for a 250-million-year-old volcanic ash bed. Large inter-aliquot variability in 4 He content and the survival of most 4 He through HF demineralization suggest that accessory zircons, known to exist in Bed 25 (), control the distribution of this isotope.The 3 He concentration and 3 …Web
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Whereas the extraterrestrial IDP component is well constrained ( 3 He/ 4 He = 2.4×10-4,[ 3 He]= 1.9×10-5 cm 3 STP g-1,Nier and Schlutter 1992), the helium isotope composition of the ...Web
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Step-heat experiments indicate rapid diffusion of extraterrestrial helium from sediments heated to temperatures above ∼ 70 °C. Given the likelihood of burial and associated heating in Permian–Triassic age rocks, the initially unexpected absence of IDP-hosted 3 He likely indicates thermally induced diffusive loss.Web
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It seems reasonable to suppose that, if Bekki's scenario is correct, the dark matter blob and/or the cloud may be linked to the temporary factor of ∼2 increase in the influx of extraterrestrial 3 He (helium-3) seen in the sedimentary record 36–34 × 10 6 y ago (Farley et al., 1998, Farley, 2001, Mukhopadhyay et al., 2001), as well as to ...Web
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Extraterrestrial helium (He et) in ferromanganese crusts from the deep oceans is presumed to originate in micrometeorites. ... Pepin et al., 2000, 2001; Lal and Jull, 2005). These end member compositions largely overlap with those estimated here for HRPs and IDPs, inhibiting a quantitative estimate of these fractions in the currently discussed ...Web
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Furthermore, the efficient loss of helium and cosmogenic neon during heating will lead to an underestimate of the 3 He and 21 Ne exposure ages of MMs, as well as to large uncertainties for cosmic dust accretion rates derived from extraterrestrial 3 He abundances in deep-sea sediments or polar ice cores. While the relative proportions of ...Web
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Sediments contain interplanetary dust particles (IDPs) carrying extraterrestrial noble gases, such as 3 He, which have previously been used to estimate the IDP accretion flux over time and the duration of past environmental events. However, due to its high diffusivity, He can be lost by diffusion either due to frictional heating during …Web
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Constant flux proxies, such as extraterrestrial helium-3 (³He_(ET)) and excess thorium-230 (²³⁰Th_(XS)), constrain vertical mass accumulation rates independent of the biases associated with ...Web
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He in marine sediment is a two-component mixture of relatively light extraterrestrial and heavy terrestrial helium; to determine the fraction of 3 He attributable to an extraterrestrial source, we used 3 He/ 4 He ratios of 2.1 × 10 −8 and 4 × 10 −4 for the terrestrial and extraterrestrial endmembers of the mixing model, respectively (Eq.Web
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Extraterrestrial helium (He et) in ferromanganese crusts from the deep oceans is presumed to originate in micrometeorites.The carrier phase of the He et has, so far, not been identified. To address this issue we have recovered and examined several metallic micrometeorites from crust 237KD from the deep Pacific Ocean, and have …Web
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Solar-type helium (He) and neon (Ne) in the Earth's mantle were suggested to be the result of solar-wind loaded extraterrestrial dust that accumulated in deep-sea sediments and was subducted into the Earth's mantle. To obtain additional constraints on this hypothesis, we analysed He, Ne and argon (Ar) in high pressure–low temperature …Web
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An extraterrestrial origin for a carbonaceous, diamond-bearing and silicate-free stone named "Hypatia", found in 1996 in southwest Egypt, was determined in 2013 and confirmed in 2015 on the basis of argon, helium, neon, xenon and nitrogen isotope characteristics. ... found in 1996 in southwest Egypt, was determined in 2013 and …Web
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Almost 40 years after the discovery of extraterrestrial helium in seafloor sediments, renewed attention is being focused on using helium as a proxy for the sedimentary abundance of extraterrestrial debris. Extraterrestrial He is carried to the seafloor by the finest fraction of interplanetary dust and is retained in at least some sediments for …Web
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Analyses of marine carbonates through the interval 63.9 to 65.4 million years ago indicate a near-constant flux of extraterrestrial helium-3, a tracer of the accretion …Web
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A.L. Myers and F. Siperstein, "Characterization of adsorbents by energy profile of adsorbed molecules", Colloids and Surfaces A 187-188, 73-81 (2001). Article [PDF] O. Talu and A.L. Myers, "Molecular simulation of adsorption: Gibbs dividing surface and comparison with experiment", AIChE J. 47, 1160-1168 (2001).Web
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Extraterrestrial He is carried to the seafloor by the finest fraction of interplanetary dust and is retained in at least some sediments for hundreds of millions of years. Helium isotope …Web
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Helium concentration and isotopic composition were measured in a suite of samples across the Permian–Triassic boundary at Opal Creek, Canada, to determine whether high extraterrestrial helium concentrations are associated with a possible extinction-inducing impact event at this time. No extraterrestrial 3 He was detected, …Web
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Since the helium and argon found in PTB fullerenes were isotopically similar to that found in meteorites, Becker et al. (2001) suggested that the fullerenes must have come from a meteorite.Web
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9 MARCH 2001 VOL 291 SCIENCE A Short Duration of the Cretaceous-Tertiary Boundary Event: Evidence from Extraterrestrial Helium-3 S. …Web
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February 23, 2001 Source: University Of Washington ... For instance, terrestrial helium is mostly helium-4 and contains only a small amount of helium-3, while extraterrestrial helium - the kind ...Web
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Helium in dust separated from kilogram-sized ice samples from the Vostok ice core site in East Antarctica has an isotopic composition consistent with an extraterrestrial origin. ... Higgins, S.M., 2001. Extraterrestrial tracer in the sea: evaluation and application of 3 He in interplanetary dust particles as a constant flux tracer in marine ...Web
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The extraterrestrial 3 He accumulation rate in ELT49-53 from 3.2 to 1.7 Ma was 0.88 ± 0.26 × 10 −12 cm 3 STP/g/kyr, ... Farley, K.A., 2001. Extraterrestrial helium in seafloor sediments: identification, characteristics, and accretion rate... K.A. Farley et al.Web
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