scholarly journals Periodicity of Cosmic-ray Exposure Ages of Iron Meteorites: Implication for Periodic Perturbation of the Asteroid Belt.

2001 ◽  
Vol 49 (5) ◽  
pp. 207-210 ◽  
Author(s):  
Teruyuki MARUOKA
Keyword(s):  
Cosmic Ray ◽  
Periodic Perturbation ◽  
Asteroid Belt ◽  
Iron Meteorites ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

scholarly journals 3. Fragmentation of Asteroids and Delivery of Fragments to Earth

1977 ◽  
Vol 39 ◽  
pp. 283-291 ◽  
Author(s):  
G. W. Wetherill
Keyword(s):  
Cosmic Ray ◽  
Asteroid Belt ◽  
Combined Effects ◽  
Iron Meteorites ◽  
Exposure Age ◽  
Impact Rate ◽  
Dynamical Time ◽  
Spectrophotometric Data ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Earth-impacting meteoroids are derived from both comets and asteroids, and some uncertainty still exists regarding with which of these bodies some stone meteorites should be identified. In contrast, the long cosmic ray exposure ages of iron meteorites strongly suggest a long-lived asteroidal source capable of providing ~108 g/yr of this material to the earth’s surface over at least much of solar system history. Spectrophotometric data show that differentiated asteroids are concentrated in the inner portion of the asteroid belt. The orbital histories of fragments of inner belt asteroids are investigated, considering the combined effects of close planetary encounters, secular perturbations, and secular resonances. Particular attention is given to the low inclination (<15°) objects with small semimajcr axis (2.1 to 2.6 A.U.), which can make fairly close approaches to Mars (<0.1 A.U.). It is found that the annual yield and dynamical lifetime of collision fragments of these asteroids is in agreement with the observed impact rate and exposure age of iron meteorites. A smaller yield of stone meteorites (-107 g/yr) is expected, because elimination of these objects by collision is probable on the long dynamical time scaTe. Achondrites could be produced in this way; the yield is probably too low to account for chondrites. Chondrites could possibly be derived indirectly from these bodies insofar as these asteroids are also sources of Apollo and Amor objects.

Strahlungsalter einiger Eisenmeteorite

1964 ◽  
Vol 19 (3) ◽  
pp. 341-346 ◽  
Author(s):  
H. Voshage ◽  
D. C. Hess
Keyword(s):  
Cosmic Ray ◽  
Washington County ◽  
Iron Meteorites ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Continuing investigations described earlier the cosmic-ray exposure ages of eight iron meteorites have been determined using the 40K/41K-method. The results are: Canyon Diablo 655 + 65 Myrs, Dayton 215 ± 85 Myrs, Grant 695 ±55 Myrs, Morradal 155 ± 95 Myrs, Norfolk 680 ± 55 Myrs, Norfork 605 ± 75 Myrs, Piñon 695 ± 125 Myrs, Washington County 610 ± 70 Myrs.

The Asteroidal Planet as the Origin of Comets

1978 ◽  
Vol 41 ◽  
pp. 89-99
Author(s):  
Thomas C. Van Flandern
Keyword(s):  
Cosmic Ray ◽  
Asteroid Belt ◽  
Supporting Evidence ◽  
Long Period ◽  
Chondritic Meteorites ◽  
Break Up ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages ◽  
Period Comet

AbstractRecently, M. W. Ovenden has raised seemingly plausible dynamical arguments which suggest that a 90-earth-mass planet existed in the present location of the asteroid belt until 16×106 years ago, and then rapidly disintegrated. He mentions supporting evidence from the cosmic ray exposure ages of chondritic meteorites. If the long-period comets originated from the recent disintegration of such a planet, several otherwise improbable characteristics of their orbits would be predicted, including a tendency for those orbits which are least perturbed to return to the site of the original break-up. In this investigation, we compare observed characteristics of long-period comet orbits with expected characteristics, based on the missing planet hypothesis. The conclusion is that long-period comet orbits are wholly consistent with the hypothesis; indeed, certain of their characteristics are difficult to explain in any other way.

Cosmic ray exposure ages of iron meteorites by the Ne21/Al26method

1965 ◽  
Vol 70 (6) ◽  
pp. 1473-1489 ◽  
Author(s):  
Michael E. Lipschutz ◽  
Peter Signer ◽  
Edward Anders
Keyword(s):  
Cosmic Ray ◽  
Iron Meteorites ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Cosmic ray exposure ages of tektites by the fission-track technique

1965 ◽  
Vol 70 (6) ◽  
pp. 1491-1496 ◽  
Author(s):  
R. L. Fleischer ◽  
C. W. Naeser ◽  
P. B. Price ◽  
R. M. Walker ◽  
M. Maurette
Keyword(s):  
Fission Track ◽  
Cosmic Ray ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

40Ar-39Ar and cosmic-ray exposure ages of nakhlites-Nakhla, Lafayette, Governador Valadares-and Chassigny

2011 ◽  
Vol 46 (9) ◽  
pp. 1397-1417 ◽  
Author(s):  
Ekaterina V. KOROCHANTSEVA ◽  
Susanne P. SCHWENZER ◽  
Alexei I. BUIKIN ◽  
Jens HOPP ◽  
Ulrich OTT ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages

Meteorites with short cosmic-ray exposure ages, as determined from their Al26 content

1967 ◽  
Vol 31 (10) ◽  
pp. 1793-1809 ◽  
Author(s):  
Dieter Heymann ◽  
Edward Anders ◽  
M.W Rowe
Keyword(s):  
Cosmic Ray ◽  
Exposure Ages ◽  
Cosmic Ray Exposure Ages
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